Technical Tip: After upgrading to v7.4.7, system emails are sent with MAIL FROM equal to MAIL TO when no SMTP authentication is configured

Starting from v7.4.4, Fortinet introduced a change in the default email notification behavior. This includes all system-generated emails, even when using a custom SMTP server.

Key behavior:

• If no SMTP username is configured, the system sets MAIL FROM equal to MAIL TO.
• The reply-to field is automatically set to DoNotReply@fortinet-notifications.com, and cannot be customized.
• If a username is configured, the MAIL FROM will be set to that username.

To override the behavior and define a specific sender, configure SMTP authentication with a valid email identity.

CLI Example:

config system email-server
    set server "smtp.yourdomain.com"
    set security starttls
    set authenticate enable
    set username "noreply@yourdomain.com"
    set password ENC <encrypted_password>
end

After applying these changes, FortiGate will send emails using the username as the MAIL FROM value, restoring the expected behavior for FortiToken and other email-based features.

Related documents:

Updated default email notification server 7.4.4