diff --git a/opwen_email_server/services/sendgrid.py b/opwen_email_server/services/sendgrid.py
index 3ced8e6b..e4d06198 100644
--- a/opwen_email_server/services/sendgrid.py
+++ b/opwen_email_server/services/sendgrid.py
@@ -15,6 +15,7 @@
 from opwen_email_server.constants.sendgrid import INBOX_URL
 from opwen_email_server.constants.sendgrid import MAILBOX_URL
 from opwen_email_server.utils.log import LogMixin
+from opwen_email_server.utils.serialization import to_base64
 
 
 class SendSendgridEmail(LogMixin):
@@ -99,14 +100,14 @@ def _create_email(self, email: dict, email_id: str) -> Mail:
     @classmethod
     def _create_attachment(cls, attachment: dict) -> Attachment:
         filename = attachment.get('filename', '')
-        content = attachment.get('content', '')
+        content = attachment.get('content', b'')
 
         mail_attachment = Attachment()
         mail_attachment.disposition = 'attachment'
         mail_attachment.filename = filename
         mail_attachment.content_id = filename
         mail_attachment.type = guess_type(filename)[0]
-        mail_attachment.content = content
+        mail_attachment.content = to_base64(content)
 
         return mail_attachment