Configurable framework agnostic plain Ruby email validator. Verify email via Regex, DNS, SMTP and even more. Be sure that email address valid and exists.

Actual and maintainable documentation 📚 for developers is living here.

Synopsis

Email validation is a tricky thing. There are a number of different ways to validate an email address and all mechanisms must conform with the best practices and provide proper validation. The Truemail gem helps you validate emails via regex pattern, presence of DNS records, and real existence of email account on a current email server.

Syntax Checking: Checks the email addresses via regex pattern.

Mail Server Existence Check: Checks the availability of the email address domain using DNS records.

Mail Existence Check: Checks if the email address really exists and can receive email via SMTP connections and email-sending emulation techniques.

Also Truemail gem allows performing an audit of the host in which runs.

Features

Configurable validator, validate only what you need
Supporting of internationalized emails (EAI)
Whitelist/blacklist validation layers
Ability to configure different MX/SMTP validation flows
Ability to configure DEA validation flow
Simple SMTP debugger
Event logger
Host auditor tools (helps to detect common host problems interfering to proper email verification)
JSON serializers
Ability to use the library as independent stateless microservice (Truemail Server)

Requirements

Ruby MRI 2.5.0+

Installation

Add this line to your application's Gemfile:

gem 'truemail'

And then execute:

bundle

Or install it yourself as:

gem install truemail

Usage

Configuration features

You can use global gem configuration or custom independent configuration. Available configuration options:

verifier email
verifier domain
email pattern
SMTP error body pattern
connection timeout
response timeout
connection attempts
default validation type
validation type for domains
whitelisted emails
blacklisted emails
whitelisted domains
blacklisted domains
whitelist validation
blacklisted mx ip-addresses
custom DNS gateway(s)
RFC MX lookup flow
SMTP port number
SMTP fail fast
SMTP safe check
event logger
JSON serializer

Setting global configuration

To have an access for Truemail.configuration and gem configuration features, you must configure it first as in the example below:

require 'truemail'

Truemail.configure do |config|
  # Required parameter. Must be an existing email on behalf of which verification will be performed
  config.verifier_email = 'verifier@example.com'

  # Optional parameter. Must be an existing domain on behalf of which verification will be performed.
  # By default verifier domain based on verifier email
  config.verifier_domain = 'somedomain.com'

  # Optional parameter. You can override default regex pattern
  config.email_pattern = /regex_pattern/

  # Optional parameter. You can override default regex pattern
  config.smtp_error_body_pattern = /regex_pattern/

  # Optional parameter. Connection timeout in seconds.
  # It is equal to 2 by default.
  config.connection_timeout = 1

  # Optional parameter. A SMTP server response timeout in seconds.
  # It is equal to 2 by default.
  config.response_timeout = 1

  # Optional parameter. Total of connection attempts. It is equal to 2 by default.
  # This parameter uses in mx lookup timeout error and smtp request (for cases when
  # there is one mx server).
  config.connection_attempts = 3

  # Optional parameter. You can predefine default validation type for
  # Truemail.validate('email@email.com') call without with-parameter
  # Available validation types: :regex, :mx, :mx_blacklist, :smtp
  config.default_validation_type = :mx

  # Optional parameter. You can predefine which type of validation will be used for domains.
  # Also you can skip validation by domain.
  # Available validation types: :regex, :mx, :mx_blacklist, :smtp
  # This configuration will be used over current or default validation type parameter
  # All of validations for 'somedomain.com' will be processed with regex validation only.
  # And all of validations for 'otherdomain.com' will be processed with mx validation only.
  # It is equal to empty hash by default.
  config.validation_type_for = { 'somedomain.com' => :regex, 'otherdomain.com' => :mx }

  # Optional parameter. Validation of email which contains whitelisted emails always will
  # return true. Other validations will not processed even if it was defined in validation_type_for
  # It is equal to empty array by default.
  config.whitelisted_emails = %w[user@somedomain1.com user@somedomain2.com]

  # Optional parameter. Validation of email which contains blacklisted emails always will
  # return false. Other validations will not processed even if it was defined in validation_type_for
  # It is equal to empty array by default.
  config.blacklisted_emails = %w[user@somedomain3.com user@somedomain4.com]

  # Optional parameter. Validation of email which contains whitelisted domain always will
  # return true. Other validations will not processed even if it was defined in validation_type_for
  # It is equal to empty array by default.
  config.whitelisted_domains = %w[somedomain1.com somedomain2.com]

  # Optional parameter. Validation of email which contains blacklisted domain always will
  # return false. Other validations will not processed even if it was defined in validation_type_for
  # It is equal to empty array by default.
  config.blacklisted_domains = %w[somedomain3.com somedomain4.com]

  # Optional parameter. With this option Truemail will validate email which contains whitelisted
  # domain only, i.e. if domain whitelisted, validation will passed to Regex, MX or SMTP validators.
  # Validation of email which not contains whitelisted domain always will return false.
  # It is equal false by default.
  config.whitelist_validation = true

  # Optional parameter. With this option Truemail will filter out unwanted mx servers via
  # predefined list of ip addresses. It can be used as a part of DEA (disposable email
  # address) validations. It is equal to empty array by default.
  config.blacklisted_mx_ip_addresses = %w[1.1.1.1 2.2.2.2]

  # Optional parameter. This option will provide to use custom DNS gateway when Truemail
  # interacts with DNS. Valid port numbers are in the range 1-65535. If you won't specify
  # nameserver's ports Truemail will use default DNS TCP/UDP port 53. By default Truemail
  # uses DNS gateway from system settings and this option is equal to empty array.
  config.dns = %w[10.0.0.1 10.0.0.2:54]

  # Optional parameter. This option will provide to use not RFC MX lookup flow.
  # It means that MX and Null MX records will be cheked on the DNS validation layer only.
  # By default this option is disabled.
  config.not_rfc_mx_lookup_flow = true

  # Optional parameter. SMTP port number. It is equal to 25 by default.
  config.smtp_port = 2525

  # Optional parameter. This option will provide to use smtp fail fast behavior. When
  # smtp_fail_fast = true it means that Truemail ends smtp validation session after first
  # attempt on the first mx server in any fail cases (network connection/timeout error,
  # smtp validation error). This feature helps to reduce total time of SMTP validation
  # session up to 1 second. By default this option is disabled.
  config.smtp_fail_fast = true

  # Optional parameter. This option will be parse bodies of SMTP errors. It will be helpful
  # if SMTP server does not return an exact answer that the email does not exist
  # By default this option is disabled, available for SMTP validation only.
  config.smtp_safe_check = true

  # Optional parameter. This option will enable tracking events. You can print tracking
  # events to stdout, write to file or both of these. Logger instance by default is Logger
  # instance from Ruby stdlib. You can override this behavior. See how to do it in the
  # examples below. Tracking event by default is :error
  # Available tracking event: :all, :unrecognized_error, :recognized_error, :error
  config.logger = {
    tracking_event: :all,
    stdout: true,
    log_absolute_path: '/home/app/log/truemail.log'
  }
end

Read global configuration

After successful configuration, you can read current Truemail configuration instance anywhere in your application.

Truemail.configuration

=> #<Truemail::Configuration:0x000055590cb17b40
 @connection_timeout=1,
 @email_pattern=/regex_pattern/,
 @smtp_error_body_pattern=/regex_pattern/,
 @response_timeout=1,
 @connection_attempts=3,
 @default_validation_type=:mx,
 @validation_type_by_domain={"somedomain.com" => :regex, "otherdomain.com" => :mx},
 @whitelisted_emails=["user@somedomain1.com", "user@somedomain2.com"],
 @blacklisted_emails=["user@somedomain3.com", "user@somedomain4.com"],
 @whitelisted_domains=["somedomain1.com", "somedomain2.com"],
 @blacklisted_domains=["somedomain3.com", "somedomain4.com"],
 @whitelist_validation=true,
 @blacklisted_mx_ip_addresses=["1.1.1.1", "2.2.2.2"],
 @dns=["10.0.0.1", "10.0.0.2:54"],
 @verifier_domain="somedomain.com",
 @verifier_email="verifier@example.com",
 @not_rfc_mx_lookup_flow=true,
 @smtp_port=2525,
 @smtp_fail_fast=true,
 @smtp_safe_check=true,
 @logger=#<Truemail::Logger:0x0000557f837450b0
   @event=:all, @file="/home/app/log/truemail.log", @custom_logger=nil @stdout=true>>

Update global configuration

Truemail.configuration.connection_timeout = 3
=> 3
Truemail.configuration.response_timeout = 4
=> 4
Truemail.configuration.connection_attempts = 1
=> 1

Truemail.configuration
=> #<Truemail::Configuration:0x000055590cb17b40
 @connection_timeout=3,
 @email_pattern=/regex_pattern/,
 @smtp_error_body_pattern=/regex_pattern/,
 @response_timeout=4,
 @connection_attempts=1,
 @default_validation_type=:mx,
 @validation_type_by_domain={"somedomain.com" => :regex, "otherdomain.com" => :mx},
 @whitelisted_emails=["user@somedomain1.com", "user@somedomain2.com"],
 @blacklisted_emails=["user@somedomain3.com", "user@somedomain4.com"],
 @whitelisted_domains=["somedomain1.com", "somedomain2.com"],
 @blacklisted_domains=["somedomain3.com", "somedomain4.com"],
 @whitelist_validation=true,
 @blacklisted_mx_ip_addresses=["1.1.1.1", "2.2.2.2"],
 @dns=["10.0.0.1", "10.0.0.2:54"],
 @verifier_domain="somedomain.com",
 @verifier_email="verifier@example.com",
 @not_rfc_mx_lookup_flow=true,
 @smtp_port=2525,
 @smtp_fail_fast=true,
 @smtp_safe_check=true,
 @logger=#<Truemail::Logger:0x0000557f837450b0
   @event=:all, @file="/home/app/log/truemail.log", @custom_logger=nil @stdout=true>>

Reset global configuration

Also you can reset Truemail configuration.

Truemail.reset_configuration!
=> nil
Truemail.configuration
=> nil

Using custom independent configuration

Allows to use independent configuration for each validation/audition instance. When using this feature you do not need to have Truemail global configuration.

custom_configuration = Truemail::Configuration.new do |config|
  config.verifier_email = 'verifier@example.com'
end

Truemail.validate('email@example.com', custom_configuration: custom_configuration)
Truemail.valid?('email@example.com', custom_configuration: custom_configuration)
Truemail.host_audit('email@example.com', custom_configuration: custom_configuration)

Please note, you should have global or custom configuration for use Truemail gem.

Validation features

Whitelist/Blacklist check

Whitelist/Blacklist check is zero validation level. You can define white and black emails/domains lists. It means that validation of email which contains whitelisted email or domain always will return true, and for blacklisted email or domain will return false.

Please note, other validations will not processed even if it was defined in validation_type_for.

Sequence of domain list check:

Whitelist check
Whitelist validation check
Blacklist check

Example of usage:

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.whitelisted_emails = %w[user@somedomain1.com user@somedomain2.com]
  config.blacklisted_emails = %w[user@somedomain3.com user@somedomain4.com]
  config.whitelisted_domains = %w[white-domain.com somedomain.com]
  config.blacklisted_domains = %w[black-domain.com somedomain.com]
  config.validation_type_for = { 'somedomain.com' => :mx }
end

Whitelist case

When email in whitelist, validation type will be redefined. Validation result returns true

Truemail.validate('email@white-domain.com')

#<Truemail::Validator:0x000055b8429f3490
  @result=#<struct Truemail::Validator::Result
    success=true,
    email="email@white-domain.com",
    domain="white-domain.com",
    mail_servers=[],
    errors={},
    smtp_debug=nil>,
    configuration=#<Truemail::Configuration:0x00005629f801bd28
     @whitelisted_emails=["user@somedomain1.com", "user@somedomain2.com"],
     @blacklisted_emails=["user@somedomain3.com", "user@somedomain4.com"],
     @blacklisted_domains=["black-domain.com", "somedomain.com"],
     @blacklisted_mx_ip_addresses=[],
     @dns=[],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @not_rfc_mx_lookup_flow=false,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={"somedomain.com"=>:mx},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=false,
     @whitelisted_domains=["white-domain.com", "somedomain.com"]>,
  @validation_type=:whitelist>

Whitelist validation case

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.whitelisted_domains = %w[white-domain.com]
  config.whitelist_validation = true
end

When email domain in whitelist and whitelist_validation is sets equal to true validation type will be passed to other validators. Validation of email which not contains whitelisted domain always will return false.

Email has whitelisted domain

Truemail.validate('email@white-domain.com', with: :regex)

#<Truemail::Validator:0x000055b8429f3490
  @result=#<struct Truemail::Validator::Result
    success=true,
    email="email@white-domain.com",
    domain="white-domain.com",
    mail_servers=[],
    errors={},
    smtp_debug=nil>,
    configuration=
    #<Truemail::Configuration:0x0000563f0d2605c8
     @whitelisted_emails=[],
     @blacklisted_emails=[],
     @blacklisted_domains=[],
     @blacklisted_mx_ip_addresses=[],
     @dns=[],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @not_rfc_mx_lookup_flow=false,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=true,
     @whitelisted_domains=["white-domain.com"]>,
  @validation_type=:regex>

Email hasn't whitelisted domain

Truemail.validate('email@domain.com', with: :regex)

#<Truemail::Validator:0x000055b8429f3490
  @result=#<struct Truemail::Validator::Result
    success=false,
    email="email@domain.com",
    domain="domain.com",
    mail_servers=[],
    errors={},
    smtp_debug=nil>,
    configuration=
    #<Truemail::Configuration:0x0000563f0cd82ab0
     @whitelisted_emails=[],
     @blacklisted_emails=[],
     @blacklisted_domains=[],
     @blacklisted_mx_ip_addresses=[],
     @dns=[],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @not_rfc_mx_lookup_flow=false,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=true,
     @whitelisted_domains=["white-domain.com"]>,
  @validation_type=:blacklist>

Blacklist case

When email in blacklist, validation type will be redefined too. Validation result returns false.

Truemail.validate('email@black-domain.com')

#<Truemail::Validator:0x000023y8429f3493
  @result=#<struct Truemail::Validator::Result
    success=false,
    email="email@black-domain.com",
    domain="black-domain.com",
    mail_servers=[],
    errors={},
    smtp_debug=nil>,
    configuration=
    #<Truemail::Configuration:0x0000563f0d36f4f0
     @whitelisted_emails=[],
     @blacklisted_emails=[],
     @blacklisted_domains=[],
     @blacklisted_mx_ip_addresses=[],
     @dns=[],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @not_rfc_mx_lookup_flow=false,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=true,
     @whitelisted_domains=["white-domain.com"]>,
  @validation_type=:blacklist>

Duplication case

Validation result for this email returns true, because it was found in whitelisted domains list first. Also validation_type for this case will be redefined.

Truemail.validate('email@somedomain.com')

#<Truemail::Validator:0x000055b8429f3490
  @result=#<struct Truemail::Validator::Result
    success=true,
    email="email@somedomain.com",
    domain="somedomain.com",
    mail_servers=[],
    errors={},
    smtp_debug=nil>,
    configuration=
    #<Truemail::Configuration:0x0000563f0d3f8fc0
     @whitelisted_emails=[],
     @blacklisted_emails=[],
     @blacklisted_domains=[],
     @blacklisted_mx_ip_addresses=[],
     @dns=[],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @not_rfc_mx_lookup_flow=false,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=true,
     @whitelisted_domains=["white-domain.com"]>,
  @validation_type=:whitelist>

Regex validation

Validation with regex pattern is the first validation level. It uses whitelist/blacklist check before running itself.

[Whitelist/Blacklist] -> [Regex validation]

By default this validation not performs strictly following RFC 5322 standard, so you can override Truemail default regex pattern if you want.

Example of usage:

With default regex pattern

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
end

Truemail.validate('email@example.com', with: :regex)

=> #<Truemail::Validator:0x000055590cc9bdb8
  @result=
    #<struct Truemail::Validator::Result
      success=true,
      email="email@example.com",
      domain="example.com",
      mail_servers=[],
      errors={},
      smtp_debug=nil>,
      configuration=
      #<Truemail::Configuration:0x000055aa56a54d48
       @whitelisted_emails=[],
       @blacklisted_emails=[],
       @blacklisted_domains=[],
       @blacklisted_mx_ip_addresses=[],
       @dns=[],
       @connection_attempts=2,
       @connection_timeout=2,
       @default_validation_type=:smtp,
       @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
       @response_timeout=2,
       @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
       @not_rfc_mx_lookup_flow=false,
       @smtp_port=25,
       @smtp_fail_fast=false,
       @smtp_safe_check=false,
       @validation_type_by_domain={},
       @verifier_domain="example.com",
       @verifier_email="verifier@example.com",
       @whitelist_validation=false,
       @whitelisted_domains=[]>,
  @validation_type=:regex>

With custom regex pattern

You should define your custom regex pattern in a gem configuration before.

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.email_pattern = /regex_pattern/
end

Truemail.validate('email@example.com', with: :regex)

=> #<Truemail::Validator:0x000055590ca8b3e8
  @result=
    #<struct Truemail::Validator::Result
      success=true,
      email="email@example.com",
      domain="example.com",
      mail_servers=[],
      errors={},
      smtp_debug=nil>,
      configuration=
      #<Truemail::Configuration:0x0000560e58d80830
       @whitelisted_emails=[],
       @blacklisted_emails=[],
       @blacklisted_domains=[],
       @blacklisted_mx_ip_addresses=[],
       @dns=[],
       @connection_attempts=2,
       @connection_timeout=2,
       @default_validation_type=:smtp,
       @email_pattern=/regex_pattern/,
       @response_timeout=2,
       @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
       @not_rfc_mx_lookup_flow=false,
       @smtp_port=25,
       @smtp_fail_fast=false,
       @smtp_safe_check=false,
       @validation_type_by_domain={},
       @verifier_domain="example.com",
       @verifier_email="verifier@example.com",
       @whitelist_validation=false,
       @whitelisted_domains=[]>,
  @validation_type=:regex>

MX validation

In fact it's DNS validation because it checks not MX records only. DNS validation is the second validation level, historically named as MX validation. It uses Regex validation before running itself. When regex validation has completed successfully then runs itself.

[Whitelist/Blacklist] -> [Regex validation] -> [MX validation]

Please note, Truemail MX validator not performs strict compliance of the RFC 5321 standard for best validation outcome.

RFC MX lookup flow

Truemail MX lookup based on RFC 5321. It consists of 3 substeps: MX, CNAME and A record resolvers. The point of each resolver is attempt to extract the mail servers from email domain. If at least one server exists that validation is successful. Iteration is processing until resolver returns true.

Example of usage:

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
end

Truemail.validate('email@example.com', with: :mx)

=> #<Truemail::Validator:0x000055590c9c1c50
  @result=
    #<struct Truemail::Validator::Result
      success=true,
      email="email@example.com",
      domain="example.com",
      mail_servers=["127.0.1.1", "127.0.1.2"],
      errors={},
      smtp_debug=nil>,
      configuration=
      #<Truemail::Configuration:0x0000559b6e44af70
       @whitelisted_emails=[],
       @blacklisted_emails=[],
       @blacklisted_domains=[],
       @blacklisted_mx_ip_addresses=[],
       @dns=[],
       @connection_attempts=2,
       @connection_timeout=2,
       @default_validation_type=:smtp,
       @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
       @response_timeout=2,
       @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
       @not_rfc_mx_lookup_flow=false,
       @smtp_port=25,
       @smtp_fail_fast=false,
       @smtp_safe_check=false,
       @validation_type_by_domain={},
       @verifier_domain="example.com",
       @verifier_email="verifier@example.com",
       @whitelist_validation=false,
       @whitelisted_domains=[]>,
  @validation_type=:mx>

Not RFC MX lookup flow

Also Truemail has possibility to use not RFC MX lookup flow. It means that will be used only one MX resolver on the DNS validation layer. By default this option is disabled.

Example of usage:

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.not_rfc_mx_lookup_flow = true
end

Truemail.validate('email@example.com', with: :mx)

=> #<Truemail::Validator:0x000055590c9c1c50
  @result=
    #<struct Truemail::Validator::Result
      success=true,
      email="email@example.com",
      domain="example.com",
      mail_servers=["127.0.1.1", "127.0.1.2"],
      errors={},
      smtp_debug=nil>,
      configuration=
      #<Truemail::Configuration:0x0000559b6e44af70
       @whitelisted_emails=[],
       @blacklisted_emails=[],
       @blacklisted_domains=[],
       @blacklisted_mx_ip_addresses=[],
       @dns=[],
       @connection_attempts=2,
       @connection_timeout=2,
       @default_validation_type=:smtp,
       @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
       @response_timeout=2,
       @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
       @not_rfc_mx_lookup_flow=true,
       @smtp_port=25,
       @smtp_fail_fast=false,
       @smtp_safe_check=false,
       @validation_type_by_domain={},
       @verifier_domain="example.com",
       @verifier_email="verifier@example.com",
       @whitelist_validation=false,
       @whitelisted_domains=[]>,
  @validation_type=:mx>

MX blacklist validation

MX blacklist validation is the third validation level. This layer provides checking extracted mail server(s) IP address from MX validation with predefined blacklisted IP addresses list. It can be used as a part of DEA (disposable email address) validations.

[Whitelist/Blacklist] -> [Regex validation] -> [MX validation] -> [MX blacklist validation]

Example of usage:

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.blacklisted_mx_ip_addresses = %w[127.0.1.2]
end

Truemail.validate('email@example.com', with: :mx_blacklist)

=> #<Truemail::Validator:0x00007fca0c8aea70
 @result=
  #<struct Truemail::Validator::Result
   success=false,
   email="email@example.com",
   domain="example.com",
   mail_servers=["127.0.1.1", "127.0.1.2"],
   errors={:mx_blacklist=>"blacklisted mx server ip address"},
   smtp_debug=nil,
   configuration=
    #<Truemail::Configuration:0x00007fca0c8aeb38
     @whitelisted_emails=[],
     @blacklisted_emails=[],
     @blacklisted_domains=[],
     @blacklisted_mx_ip_addresses=["127.0.1.2"],
     @connection_attempts=2,
     @connection_timeout=2,
     @default_validation_type=:smtp,
     @dns=[],
     @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-.+]*)@((?i-mx:[\p{L}0-9]+([\-.]{1}[\p{L}0-9]+)*\.\p{L}{2,63}))\z)/,
     @not_rfc_mx_lookup_flow=false,
     @response_timeout=2,
     @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
     @smtp_port=25,
     @smtp_fail_fast=false,
     @smtp_safe_check=false,
     @validation_type_by_domain={},
     @verifier_domain="example.com",
     @verifier_email="verifier@example.com",
     @whitelist_validation=false,
     @whitelisted_domains=[]>>,
 @validation_type=:mx_blacklist>

SMTP validation

SMTP validation is a final, fourth validation level. This type of validation tries to check real existence of email account on a current email server. This validation runs a chain of previous validations and if they're complete successfully then runs itself.

[Whitelist/Blacklist] -> [Regex validation] -> [MX validation] -> [MX blacklist validation] -> [SMTP validation]

If total count of MX servers is equal to one, Truemail::Smtp validator will use value from Truemail.configuration.connection_attempts as connection attempts. By default it's equal 2.

By default, you don't need pass with-parameter to use it. Example of usage is specified below:

SMTP fail fast enabled

Truemail can use fail fast behavior for SMTP validation layer. When smtp_fail_fast = true it means that truemail ends smtp validation session after first attempt on the first mx server in any fail cases (network connection/timeout error, smtp validation error). This feature helps to reduce total time of SMTP validation session up to 1 second.

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.smtp_fail_fast = true
end

Truemail.validate('email@example.com')

# SMTP validation failed, smtp fail fast validation scenario
=> #<Truemail::Validator:0x00007fdc4504f460
    @result=
      #<struct Truemail::Validator::Result
        success=false,
        email="email@example.com",
        domain="example.com",
        mail_servers=["127.0.1.1", "127.0.1.2", "127.0.1.3"], # there are 3 mail servers in a row
        errors={:smtp=>"smtp error"},
        smtp_debug=
          [#<Truemail::Validate::Smtp::Request:0x00007fdc43150b90 # but iteration has been stopped after the first failure
            @attempts=nil,
            @configuration=
              #<Truemail::Validate::Smtp::Request::Configuration:0x00007fdc43150b18
                @connection_timeout=2,
                @response_timeout=2,
                @verifier_domain="example.com",
                @verifier_email="verifier@example.com">,
            @email="email@example.com",
            @host="127.0.1.1",
            @response=
              #<struct Truemail::Validate::Smtp::Response
                port_opened=false,
                connection=nil,
                helo=nil,
                mailfrom=nil,
                rcptto=nil,
                errors={}>>],
        configuration=
          #<Truemail::Configuration:0x00007fdc4504f5c8
            @whitelisted_emails=[],
            @blacklisted_emails=[],
            @blacklisted_domains=[],
            @blacklisted_mx_ip_addresses=[],
            @dns=[],
            @connection_attempts=2,
            @connection_timeout=2,
            @default_validation_type=:smtp,
            @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-.+]*)@((?i-mx:[\p{L}0-9]+([\-.]{1}[\p{L}0-9]+)*\.\p{L}{2,63}))\z)/,
            @not_rfc_mx_lookup_flow=false,
            @response_timeout=2,
            @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
            @smtp_port=25,
            @smtp_fail_fast=true,
            @smtp_safe_check=false,
            @validation_type_by_domain={},
            @verifier_domain="example.com",
            @verifier_email="verifier@example.com",
            @whitelist_validation=false,
            @whitelisted_domains=[]>>,
      @validation_type=:smtp>

SMTP safe check disabled

With smtp_safe_check = false

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
end

Truemail.validate('email@example.com')

# Successful SMTP validation
=> #<Truemail::Validator:0x000055590c4dc118
  @result=
    #<struct Truemail::Validator::Result
      success=true,
      email="email@example.com",
      domain="example.com",
      mail_servers=["127.0.1.1", "127.0.1.2"],
      errors={},
      smtp_debug=nil>,
      configuration=
      #<Truemail::Configuration:0x00005615e87b9298
       @whitelisted_emails=[],
       @blacklisted_emails=[],
       @blacklisted_domains=[],
       @blacklisted_mx_ip_addresses=[],
       @dns=[],
       @connection_attempts=2,
       @connection_timeout=2,
       @default_validation_type=:smtp,
       @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
       @response_timeout=2,
       @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
       @not_rfc_mx_lookup_flow=false,
       @smtp_fail_fast=false,
       @smtp_safe_check=false,
       @validation_type_by_domain={},
       @verifier_domain="example.com",
       @verifier_email="verifier@example.com",
       @whitelist_validation=false,
       @whitelisted_domains=[]>,
  @validation_type=:smtp>

# SMTP validation failed
=> #<Truemail::Validator:0x0000000002d5cee0
    @result=
      #<struct Truemail::Validator::Result
        success=false,
        email="email@example.com",
        domain="example.com",
        mail_servers=["127.0.1.1", "127.0.1.2"],
        errors={:smtp=>"smtp error"},
        smtp_debug=
          [#<Truemail::Validate::Smtp::Request:0x0000000002d49b10
            @configuration=
              #<Truemail::Validate::Smtp::Request::Configuration:0x00005615e8d21848
              @connection_timeout=2,
              @response_timeout=2,
              @verifier_domain="example.com",
              @verifier_email="verifier@example.com">,
            @email="email@example.com",
            @host="127.0.1.1",
            @attempts=nil,
            @response=
              #<struct Truemail::Validate::Smtp::Response
                port_opened=true,
                connection=true,
                helo=true,
                mailfrom=
                  #<Net::SMTP::Response:0x0000000002d5a618
                    @status="250",
                    @string="250 OK\n">,
                rcptto=false,
                errors={:rcptto=>"550 User not found\n"}>>]>,
          configuration=
            #<Truemail::Configuration:0x00005615e87b9298
             @whitelisted_emails=[],
             @blacklisted_emails=[],
             @blacklisted_domains=[],
             @blacklisted_mx_ip_addresses=[],
             @dns=[],
             @connection_attempts=2,
             @connection_timeout=2,
             @default_validation_type=:smtp,
             @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
             @response_timeout=2,
             @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
             @not_rfc_mx_lookup_flow=false,
             @smtp_port=25,
             @smtp_fail_fast=false,
             @smtp_safe_check=false,
             @validation_type_by_domain={},
             @verifier_domain="example.com",
             @verifier_email="verifier@example.com",
             @whitelist_validation=false,
             @whitelisted_domains=[]>,
    @validation_type=:smtp>

SMTP safe check enabled

With smtp_safe_check = true

require 'truemail'

Truemail.configure do |config|
  config.verifier_email = 'verifier@example.com'
  config.smtp_safe_check = true
end

Truemail.validate('email@example.com')

# Successful SMTP validation
=> #<Truemail::Validator:0x0000000002ca2c70
    @result=
      #<struct Truemail::Validator::Result
        success=true,
        email="email@example.com",
        domain="example.com",
        mail_servers=["127.0.1.1", "127.0.1.2"],
        errors={},
        smtp_debug=
          [#<Truemail::Validate::Smtp::Request:0x0000000002c95d40
            @configuration=
              #<Truemail::Validate::Smtp::Request::Configuration:0x00005615e8d21848
              @connection_timeout=2,
              @response_timeout=2,
              @verifier_domain="example.com",
              @verifier_email="verifier@example.com">,
            @email="email@example.com",
            @host="127.0.1.1",
            @attempts=nil,
            @response=
              #<struct Truemail::Validate::Smtp::Response
                port_opened=true,
                connection=false,
                helo=true,
                mailfrom=false,
                rcptto=nil,
                errors={:mailfrom=>"554 5.7.1 Client host blocked\n", :connection=>"server dropped connection after response"}>>,]>,
        configuration=
            #<Truemail::Configuration:0x00005615e87b9298
             @whitelisted_emails=[],
             @blacklisted_emails=[],
             @blacklisted_domains=[],
             @blacklisted_mx_ip_addresses=[],
             @dns=[],
             @connection_attempts=2,
             @connection_timeout=2,
             @default_validation_type=:smtp,
             @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
             @response_timeout=2,
             @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
             @not_rfc_mx_lookup_flow=false,
             @smtp_fail_fast=false,
             @smtp_safe_check=false,
             @validation_type_by_domain={},
             @verifier_domain="example.com",
             @verifier_email="verifier@example.com",
             @whitelist_validation=false,
             @whitelisted_domains=[]>,
    @validation_type=:smtp>

# SMTP validation failed
=> #<Truemail::Validator:0x0000000002d5cee0
   @result=
    #<struct Truemail::Validator::Result
      success=false,
      email="email@example.com",
      domain="example.com",
      mail_servers=["127.0.1.1", "127.0.1.2"],
      errors={:smtp=>"smtp error"},
      smtp_debug=
        [#<Truemail::Validate::Smtp::Request:0x0000000002d49b10
          @configuration=
              #<Truemail::Validate::Smtp::Request::Configuration:0x00005615e8d21848
              @connection_timeout=2,
              @response_timeout=2,
              @verifier_domain="example.com",
              @verifier_email="verifier@example.com">,
          @email="email@example.com",
          @host="127.0.1.1",
          @attempts=nil,
          @response=
            #<struct Truemail::Validate::Smtp::Response
              port_opened=true,
              connection=true,
              helo=true,
              mailfrom=#<Net::SMTP::Response:0x0000000002d5a618 @status="250", @string="250 OK\n">,
              rcptto=false,
              errors={:rcptto=>"550 User not found\n"}>>]>,
      configuration=
            #<Truemail::Configuration:0x00005615e87b9298
             @whitelisted_emails=[],
             @blacklisted_emails=[],
             @blacklisted_domains=[],
             @blacklisted_mx_ip_addresses=[],
             @dns=[],
             @connection_attempts=2,
             @connection_timeout=2,
             @default_validation_type=:smtp,
             @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
             @response_timeout=2,
             @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
             @not_rfc_mx_lookup_flow=false,
             @smtp_port=25,
             @smtp_fail_fast=false,
             @smtp_safe_check=false,
             @validation_type_by_domain={},
             @verifier_domain="example.com",
             @verifier_email="verifier@example.com",
             @whitelist_validation=false,
             @whitelisted_domains=[]>,
    @validation_type=:smtp>

Host audit features

Truemail gem allows performing an audit of the host in which runs. It will help to detect common host problems interfering to proper email verification.

IP audit

Checks is current Truemail host has proper internet connection and detects current host ip address.

DNS audit

Checks is verifier domain refer to current Truemail host IP address.

PTR audit

So what is a PTR record? A PTR record, or pointer record, enables someone to perform a reverse DNS lookup. This allows them to determine your domain name based on your IP address. Because generic domain names without a PTR are often associated with spammers, incoming mail servers identify email from hosts without PTR records as spam and you can't verify yours emails qualitatively.

Checks is PTR record exists for your Truemail host ip address exists and refers to current verifier domain.

Example of using

Truemail.host_audit
# Everything is good
=> #<Truemail::Auditor:0x00005580df358828
   @result=
     #<struct Truemail::Auditor::Result
       current_host_ip="127.0.0.1",
       warnings={}>,
       configuration=
        #<Truemail::Configuration:0x00005615e86327a8
         @whitelisted_emails=[],
         @blacklisted_emails=[],
         @blacklisted_domains=[],
         @blacklisted_mx_ip_addresses=[],
         @dns=[],
         @connection_attempts=2,
         @connection_timeout=2,
         @default_validation_type=:smtp,
         @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
         @response_timeout=2,
         @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
         @not_rfc_mx_lookup_flow=false,
         @smtp_port=25,
         @smtp_fail_fast=false,
         @smtp_safe_check=false,
         @validation_type_by_domain={},
         @verifier_domain="example.com",
         @verifier_email="verifier@example.com",
         @whitelist_validation=false,
         @whitelisted_domains=[]>

# Has audit warnings
=> #<Truemail::Auditor:0x00005580df358828
   @result=
     #<struct Truemail::Auditor::Result
       current_host_ip="127.0.0.1",
       warnings={
         :dns=>"A-record of verifier domain not refers to current host ip address",
         :ptr=>"PTR-record does not reference to current verifier domain"
       },
       configuration=
        #<Truemail::Configuration:0x00005615e86327a8
         @whitelisted_emails=[],
         @blacklisted_emails=[],
         @blacklisted_domains=[],
         @blacklisted_mx_ip_addresses=[],
         @dns=[],
         @connection_attempts=2,
         @connection_timeout=2,
         @default_validation_type=:smtp,
         @email_pattern=/(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\w|\-|\.|\+]*)@((?i-mx:[\p{L}0-9]+([\-\.]{1}[\p{L}0-9]+)*\.[\p{L}]{2,63}))\z)/,
         @response_timeout=2,
         @smtp_error_body_pattern=/(?=.*550)(?=.*(user|account|customer|mailbox)).*/i,
         @not_rfc_mx_lookup_flow=false,
         @smtp_port=25,
         @smtp_fail_fast=false,
         @smtp_safe_check=false,
         @validation_type_by_domain={},
         @verifier_domain="example.com",
         @verifier_email="verifier@example.com",
         @whitelist_validation=false,
         @whitelisted_domains=[]>

Event logger

Truemail gem allows to output tracking events to stdout/file or both of these. Please note, at least one of the outputs (stdout or file path) must exists. Tracking event by default is :error.

Truemail.configure do |config|
  config.logger = {
    tracking_event: :all,
    stdout: true,
    log_absolute_path: '/home/app/log/truemail.log'
    }
end

Using custom logger

By default Truemail uses Logger, default logger instance from Ruby stdlib. But you can override this behavior passing your logger instance in event logger configuration. Please note, your own logger instance should have the same interface as builtin stdlib Logger instance. In this case custom_logger is only one required field for logger configuration (you don't have to use stdout and log_absolute_path).

Truemail.configure do |config|
  config.logger = { custom_logger: MyCustomLogger.new }
end

Available tracking events

:all, all detected events including success validation cases
:unrecognized_error, unrecognized errors only (when smtp_safe_check = true and SMTP server does not return an exact answer that the email does not exist)
:recognized_error, recognized errors only
:error, recognized and unrecognized errors only

JSON serializers

Truemail has built in JSON serializers for Truemail::Auditor and Truemail::Validator instances, so you can represent your host audition or email validation result as json. Also you can use #as_json helper for shortcuting.

Auditor JSON serializer

Truemail::Log::Serializer::AuditorJson.call(Truemail.host_audit)

=>
# Serialized Truemail::Auditor instance
{
  "date": "2020-08-31 22:33:43 +0300",
  "current_host_ip": "127.0.0.1",
  "warnings": {
    "dns": "A-record of verifier domain not refers to current host ip address", "ptr": "PTR-record does not reference to current verifier domain"
  },
 "configuration": {
    "whitelisted_emails": null,
    "blacklisted_emails": null,
    "blacklisted_domains": null,
    "blacklisted_mx_ip_addresses": null,
    "dns": null,
    "email_pattern": "default gem value",
    "not_rfc_mx_lookup_flow": false,
    "smtp_error_body_pattern": "default gem value",
    "smtp_fail_fast": false,
    "smtp_safe_check": false,
    "validation_type_by_domain": null,
    "whitelist_validation": false,
    "whitelisted_domains": null
  }
}

Validator JSON serializer

Truemail::Log::Serializer::ValidatorJson.call(Truemail.validate('nonexistent_email@bestweb.com.ua'))

=>
# Serialized Truemail::Validator instance
{
  "date": "2019-10-28 10:15:51 +0200",
  "email": "nonexistent_email@bestweb.com.ua",
  "validation_type": "smtp",
  "success": false,
  "errors": {
    "smtp": "smtp error"
  },
  "smtp_debug": [
    {
      "mail_host": "213.180.193.89",
      "port_opened": true,
      "connection": true,
      "errors": {
        "rcptto": "550 5.7.1 No such user!\n"
      }
    }
  ],
  "configuration": {
    "whitelisted_emails": null,
    "blacklisted_emails": null,
    "blacklisted_domains": null,
    "blacklisted_mx_ip_addresses": null,
    "dns": null,
    "email_pattern": "default gem value",
    "not_rfc_mx_lookup_flow": false,
    "smtp_error_body_pattern": "default gem value",
    "smtp_fail_fast": false,
    "smtp_safe_check": false,
    "validation_type_by_domain": null,
    "whitelist_validation": false,
    "whitelisted_domains": null
  }
}

Truemail helpers

`.valid?`

You can use the .valid? helper for quick validation of email address. It returns a boolean:

# It is shortcut for Truemail.validate('email@example.com').result.valid?
Truemail.valid?('email@example.com')
=> true

`#as_json`

You can use #as_json helper for represent Truemail::Auditor or Truemail::Validator instances as json. Under the hood it uses internal json Truemail::Log::Serializer::AuditorJson and Truemail::Log::Serializer::ValidatorJson serializers:

Truemail.host_audit.as_json

=>
# Serialized Truemail::Auditor instance
{
  "date": "2020-08-31 22:33:43 +0300",
  "current_host_ip": "127.0.0.1",
  "warnings": {
    "dns": "A-record of verifier domain not refers to current host ip address", "ptr": "PTR-record does not reference to current verifier domain"
  },
 "configuration": {
    "whitelisted_emails": null,
    "blacklisted_emails": null,
    "blacklisted_domains": null,
    "blacklisted_mx_ip_addresses": null,
    "dns": null,
    "email_pattern": "default gem value",
    "not_rfc_mx_lookup_flow": false,
    "smtp_error_body_pattern": "default gem value",
    "smtp_fail_fast": false,
    "smtp_safe_check": false,
    "validation_type_by_domain": null,
    "whitelist_validation": false,
    "whitelisted_domains": null
  }
}


Truemail.validate('nonexistent_email@bestweb.com.ua').as_json

=>
# Serialized Truemail::Validator instance
{
  "date": "2020-05-10 10:00:00 +0200",
  "email": "nonexistent_email@bestweb.com.ua",
  "validation_type": "smtp",
  "success": false,
  "errors": {
    "smtp": "smtp error"
  },
  "smtp_debug": [
    {
      "mail_host": "213.180.193.89",
      "port_opened": true,
      "connection": true,
      "errors": {
        "rcptto": "550 5.7.1 No such user!\n"
      }
    }
  ],
  "configuration": {
    "whitelisted_emails": null,
    "blacklisted_emails": null,
    "blacklisted_domains": null,
    "blacklisted_mx_ip_addresses": null,
    "dns": null,
    "email_pattern": "default gem value",
    "not_rfc_mx_lookup_flow": false,
    "smtp_error_body_pattern": "default gem value",
    "smtp_fail_fast": false,
    "smtp_safe_check": false,
    "validation_type_by_domain": null,
    "whitelist_validation": false,
    "whitelisted_domains": null
  }
}

Test environment

You can stub out that validation for your test environment. Just add RSpec before action:

# spec_helper.rb

RSpec.configure do |config|
  config.before { allow(Truemail).to receive(:valid?).and_return(true) }
  # or
  config.before { allow(Truemail).to receive(:validate).and_return(true) }
  # or
  config.before { allow(Truemail).to receive_message_chain(:validate, :result, :valid?).and_return(true) }
end

Or with whitelist/blacklist Truemail feature you can define validation behavior for test and staging environment:

# config/initializers/truemail.rb

Truemail.configure do |config|
  config.verifier_email = Rails.configuration.default_sender_email

  unless Rails.env.production?
    config.whitelisted_domains = Constants::Email::WHITE_DOMAINS
    config.blacklisted_domains = Constants::Email::BLACK_DOMAINS
  end
end

Or you can use end-to-end approach and mock DNS and SMTP services with dns_mock, smtp_mock for your test environment like in example below:

# Gemfile

group :test do
  gem 'dns_mock', require: false
  gem 'smtp_mock', require: false
end

# spec/spec_helper.rb

require 'dns_mock/test_framework/rspec'
require 'smtp_mock/test_framework/rspec'

RSpec.configure do |config|
  config.include DnsMock::TestFramework::RSpec::Helper
  config.include SmtpMock::TestFramework::RSpec::Helper
end

# spec/integration_spec.rb

RSpec.describe 'integration tests' do
  let(:target_email) { random_email }
  let(:dns_mock_records) { dns_mock_records_by_email(target_email, dimension: 2) }

  before do
    dns_mock_server.assign_mocks(dns_mock_records)
    smtp_mock_server(**smtp_mock_server_options)

    Truemail.configuration.tap do |config|
      config.dns = %W[127.0.0.1:#{dns_mock_server.port}]
      config.smtp_port = smtp_mock_server.port
    end
  end

  context 'when checks real email' do
    let(:smtp_mock_server_options) { {} }

    it { expect(Truemail.validate(target_email).result).to be_valid }
  end

  context 'when checks fake email' do
    let(:smtp_mock_server_options) { { not_registered_emails: [target_email] } }

    it { expect(Truemail.validate(target_email).result).not_to be_valid }
  end
end

Truemail family

All Truemail solutions: https://truemail-rb.org

Name	Type	Description
truemail-go	go package	Configurable Golang email validator, main core
truemail server	ruby app	Lightweight rack based web API wrapper for Truemail gem
truemail-rack-docker	docker image	Lightweight rack based web API dockerized image 🐳 of Truemail server
truemail-ruby-client	ruby gem	Web API Ruby client for Truemail Server
truemail-crystal-client	crystal shard	Web API Crystal client for Truemail Server
truemail-java-client	java lib	Web API Java client for Truemail Server
truemail-rspec	ruby gem	Truemail configuration, auditor and validator RSpec helpers

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/truemail-rb/truemail. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct. Please check the open tickets. Be sure to follow Contributor Code of Conduct below and our Contributing Guidelines.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Truemail project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

Credits

The Contributors for code and awesome suggestions
The Stargazers for showing their support

Versioning

Truemail uses Semantic Versioning 2.0.0

Files

README.md

Latest commit

History

README.md

File metadata and controls

Table of Contents

Synopsis

Features

Requirements

Installation

Usage

Configuration features

Setting global configuration

Read global configuration

Update global configuration

Reset global configuration

Using custom independent configuration

Validation features

Whitelist/Blacklist check

Whitelist case

Whitelist validation case

Email has whitelisted domain

Email hasn't whitelisted domain

Blacklist case

Duplication case

Regex validation

With default regex pattern

With custom regex pattern

MX validation

RFC MX lookup flow

Not RFC MX lookup flow

MX blacklist validation

SMTP validation

SMTP fail fast enabled

SMTP safe check disabled

SMTP safe check enabled

Host audit features

IP audit

DNS audit

PTR audit

Example of using

Event logger

Using custom logger

Available tracking events

JSON serializers

Auditor JSON serializer

Validator JSON serializer

Truemail helpers

.valid?

#as_json

Test environment

Truemail family

Contributing

License

Code of Conduct

Credits

Versioning

`.valid?`

`#as_json`