Integrate with SendGrid using SMTP

  • Change your SMTP authentication username and password to your SendGrid username and password, or set up a teammate with the Mail Send permission set to “Full Access”.
  • Create an API Key and make sure it has Mail permissions.
  • Set the server host to This setting can sometimes be referred to as the external SMTP server, or relay, by some programs and services.
  • Use the string “apikey” for the SMTP username and use your API key for the password.


  • Use port 25, 2525, or 587 for unencrypted / TLS connections
  • Use port 465 for SSL connections

We recommend using port 587 to avoid potential rate limiting. 587 is also the least likely to be blocked by default corporate and residential ISP network settings.

When using SMTP, You can send 100 messages per SMTP connection at a time, and open up to 10 concurrent connections from a single server at a time.

For more information on how to integrate with SendGrid, check out our Integrate page.