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Sending emails via own SMTP

Sending emails via your own SMTP server is only available with these paid options: "Business" add-on, "Extended" add-on, standalone SMTP add-on.

If you have access to the SMTP settings, log in to Deftform and open the workspace settings "Custom SMTP / Email". You will need to enter the following credentials to set up email delivery via your own SMTP, make sure you have them ready.

  • Host
  • Port
  • Username
  • Password
  • Encryption type
  • From email address

Make sure your server can actually send emails. Oftentimes, servers need to be configured to be able to send from specific addresses such as "info@" or "noreply@" addresses.

Verification code not arriving

In order to confirm custom SMTP setup, we will send an email to your account email address. This email contains a code that needs to be entered. The email will be sent from your SMTP. If you don't receive the code, it was not possible to send the email.

Most of the time, the login credentials are simply not correct. But often, there are issues with the sending email server, often resulting in errors like this:

451 4.3.5 no-reply@example.com: Sender address rejected: Server configuration problem

You actually cannot see those errors, but we do in our logs.

This error message indicates a server configuration problem on the sending side. The error code 451 suggests there's an issue with the SMTP server configuration that's preventing it from accepting the email for delivery.

Here's what this specific error means

  • 451: This is a temporary error code indicating that the server cannot complete the requested action at this time

  • 4.3.5: This enhanced status code indicates a mail system configuration error

  • Sender address rejected: Server configuration problem: The receiving mail server is rejecting the sender address due to a configuration issue on the sending server side

Common causes for this error include

  • Incorrect or missing reverse DNS (PTR) records for your sending server

  • Missing or incorrect SPF, DKIM, or DMARC records for your domain

  • IP reputation issues with your sending server

  • Misconfigured MX records
 - Problems with the mail server software configuration

To resolve this issue, you should

  1. Check your domain's DNS configuration, particularly the MX, SPF, DKIM, and PTR records

  2. Ensure your mail server is properly configured

  3. Contact your email service provider or hosting company's support team, as they may need to fix a configuration issue on their end

If you're managing your own mail server, you'll need to review your mail server configuration files and DNS settings.

Issue setting up AWS SES

If you're using SES and are absolutely sure the login credentials are correct, check these common issues:

  • SMTP credentials are different from your AWS access key ID and secret access key. Make sure you're using the specific SMTP credentials generated for SES.
  • Verify your account is out of the SES sandbox if you're sending to non-verified recipients.
  • If you recently rotated credentials, there might be a propagation delay. Wait a few minutes and try again.
  • Ensure the IAM user has the appropriate SES sending permissions.
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