I recently found that my server’s IP was underneath a prefix that was blacklisted, so I wanted to move my server to one whose Prefix was NOT blacklisted. I took the following steps (all on Digital Ocean btw)
- Backed up a snapshot of my server, then renamed and disabled it
- Setup a new server (droplet) at a new IP and restored my backup snapshot to it
- Changed my DNS entry for the server name
- Logged into new server and checked DNS against each of my domains and mailcow showed they were all perfect
- although I could receive mail on the new server, sending was blocked my most receiving domains with variations of ’550, “5.7.1” The IP you’re using to send email is not authorized…'
- I verified all records as being correct, including PTR, so I don’t know why this would happen. Thinking perhaps it was a propagation error I waited a couple of hours, but it still happened.
Luckily I had not deleted the original server (with it’s IP intact) to I deleted the new one, renamed the old one back to my domain name, verified all records and restored to it. Now I can mostly send again, except for the few that are rejected because my prefix (though not my IP) is on some block list.
My question is: IS there something else I was supposed to do in mailcow to make this work? Regenerate DKIM keys or something else?