have you checked this documentation; Email ā Zammad documentation
you can just configure your own smtp configuration from there, instead of relying on sendmail. Or you could configure your local MTA (which probably sendmail or postfix) to either include needed headers, or to use a smarthost
Yeah, i checked and i configured it. While receiving emails works the sender instead is apparently helpdesk@g---- but the actual sender is zammad mail service and fails the mail verification then spam.
I redacted the actual mails but heres the screenshots
Yesterday i tried to remove the notification email and for good measure i removed also the account email and re-configured it. I think it fixed itself up because now i get a PASS in the spf and doesnt get flagged as spam. I am sure that i used the correct password the first time i configured it in the first setup wizard because i use a password manager and i copy pasted it. Strange