Getting error " 15] Our system has detected that this message is 421-4.7.0 suspicious due to the very low reputation of the sending IP address" when forwarding to gmail.com

Maintenance
1

I’ve setup everything ok in MiaB - I think - and my admin status shows that everything is on green for my domain, except for DNSSEC which my domain name provider doesn’t support for my extension. Still, I am getting the error

15] Our system has detected that this message is 421-4.7.0 suspicious due to the very low reputation of the sending IP address

when forwarding emails to a gmail.com address. By looking at the logs, it does seem that Gmail is blocking genuine emails too.

I’ve tried to check Google’s docs related to the matter, but I can’t find anything special that I could do. Only thing that seems relevant is that MiaB (or Postfix in this case) would change the headers or the content of the email somehow, but I don’t think that’s happening either.

And when I send emails to http://www.mail-tester.com I get a full 10/10 score.

Can anyone help me with this issue please? The domain in question is paul.fi.

EDIT: After a bit of Googeling (Question | DigitalOcean), I stumbled upon something called SRS (Sender Rewriting Scheme - Wikipedia) that apparently should be used for cases like this. Does MiaB support SRS? And is this my problem?

2

Did you see this thread? Implement SPF:SRS

Do non-forwarded emails get sent OK?

Verifying your domain with Google Postmaster Tools might help: https://support.google.com/mail/answer/6227174?hl=en

3

I did verify my domain on Google Postmaster Tools, but it’s not yet showing any information. I do hope it would tell me more in-depth what might be wrong.

Direct mails always go through (in my tests). And it’s not like all forwards would get rejected by Google, it’s just that I recently saw a trend of increasingly more emails getting stuck in the queue and unable to be delivered to Google. I was wondering if there’s anything I can do “to improve the reputation of my IP”?

4

But did you read that thread?

No, if you have already set up your domain on postmater tools, that’s as good as it gets.

5

And, of course: if people are marking your emails as spam, then Google will consider your domain spammy.

6

You can also verify your ip adres of your box with http://www.mxtoolbox.com