How to troubleshoot domains marked as Spam

If you’re using a relatively new cloud server, it may take some time before larger email providers recognize it as trustworthy and stop flagging your messages as spam.
This happens because your sending domain is associated with a new IP address, and reputation systems need time to establish a profile for it.

If your emails are being marked as spam by Gmail, Outlook, or other providers, you can test your setup at dkimvalidator.com:

1. Enter your email address in the field and click View Results.

2. Check that your domain passes both SPF and DKIM validation. If it does, your chances of avoiding spam filters are much higher.

Additional Recommendations

• Server Administration > Mail > Security > General

  • Enable Reject if originator’s domain is local and not authorized.

    • This blocks emails sent without proper login or authentication.

• Server Administration > Mail > Security > Advanced

  • Enable Reject if SMTP AUTH different from sender.

    • This rejects any connection where the sender information differs from the SMTP AUTH command.

    • Note: With this setting enabled, “send on behalf of” functionality will be disabled.