DocFraggle
I am not getting an NDR in gmail at all. These are in the mailcow postfix logs.
I work in IT, mostly Helpdesk and administrating Microsoft servers, and I work with Exchange a lot. I started dipping my toe into Linux and Docker during the lockdown, and I’m making a big push into it now. When you say these are outbound logs, I know what you mean. They look like they would be. I just sent again from my gmail, not a reply, just a test message from my gmail to my mailcow email, and I got the same error:
D252756A1B6: to=<example@gmail.com>, relay=smtp.sendgrid.net[52.204.68.213]:587, delay=0.52, delays=0.01/0.01/0.39/0.13, dsn=5.0.0, status=bounced (host smtp.sendgrid.net[52.204.68.213] said: 550 The from address does not match a verified Sender Identity. Mail cannot be sent until this error is resolved. Visit https://sendgrid.com/docs/for-developers/sending-email/sender-identity/ to see the Sender Identity requirements (in reply to end of DATA command))
It’s almost as if the mailcow server is trying to relay the message instead of delivering it internally. Is it possible I misconfigured something that would cause/allow it to do that?
