Since you use a spam filter and Google Workspace, we recommend that you use our Direct Message Injection (DMI) feature. For more information, see our DMI Configuration Guide .

If you're unable to use DMI, we recommend you first whitelist your mail server by email header. For more information, see our Whitelisting by Email Header in Google Workspace article.

After you've whitelisted your mail server, you'll need to whitelist your spam filter. Click Next below for more information.