- Plesk Onyx
- Gmail marks emails as spam. Emails are successfully delivered to other email servers.
- All checks in Gmail marked as "pass"
- Due to misconfiguration, SPF was failed previously.
- Gmail detects message as spam with the note "It's similar to messages that were detected by our spam filters" or "Why is this message in spam? It is similar to messages that were identified as spam in the past.":
Your emails to Gmail accounts are being classified as spam since they do not comply with the Bulk Sender's Guidelines.
Check Google forum with the guidelines on how to fix that.
Note: in case the above actions would not help, contact Google support.