Outgoing Emails Delivered to Spam

[Dinesh]

Hi All,

I have installed and configured Proxmox Mail Gateway (PMG) for both incoming and outgoing email traffic.

Incoming emails are working fine. However, all outgoing emails sent to Gmail and Yahoo are being delivered to the Spam/Junk folder, even though:

• SPF: Pass
• DKIM: Pass
• DMARC: Pass
• Mail Tester: 10/10 score

Could you please guide me on what additional configurations or checks should be performed on the PMG, sending mail server, DNS, or IP reputation to ensure that outgoing emails are delivered to the Inbox instead of Spam?

Any recommendations regarding PTR/rDNS, HELO/EHLO hostname, IP reputation, SMTP configuration, or Gmail/Yahoo-specific requirements would be greatly appreciated.

Thank you in advance for your guidance.

 

[mfederanko]

Both your mail servers are listed on UCEPROTECTL3, I'd try to get delisted there and check your sending behavior.

 

[Dinesh]

Thank you for your reply. There is no blocklisting now. I have checked the email again, but it is still email going to spam. However, in Gmail, all the authentication checks are showing as “PASS.”

 

[mfederanko]

If everything seems to be configured correctly there isn't much left but o get in contact with the receiver, though that might be hard for google or yahoo. I would next check googles (and yahoos) email guidelines [0] and make sure to avoid "spammy" behavior.
Google also offers its postmaster tools for deeper analysis of why mails are moved to spam, though they require a base volume of mails delivered to gmail inboxes for anything to show.

[0] https://support.google.com/mail/answer/81126?hl=en
[1] https://support.google.com/mail/answer/9981691?hl=en

 

[CRCinAU]

Another thing to check - your reverse DNS entries in your first post seem to mention pmg01 and pmg02.

From querying external DNS servers for your screenshotted PMG hosts, I see that pmg01 does not seem to have a reverse DNS entry for its IP address.

These are *very* strictly enforced by the major mail providers.

It looks like these IPs may belong to OVH, which might mean you can't sign up for Microsoft's SNDS service, however if you can, this may also be useful:
https://substrate.office.com/ip-domain-management-snds/snds/faq