Hi,
We have some SMTP servers that were migrated from old servers that were handled by CPANEL. One thing they had in common, is that we started getting this error on some ISPs – “Recipient address rejected: User unknown in local recipient table”. We didn’t have this problem on our old servers so it’s strange for us.
I’m trying to look into this deeper. Initially, we’re writing this off as an issue with the ISP (sfr.fr) but I was recently told that they are a big mail company and this kind of mistake doesn’t usually happen on their side. So I’m forced to look at possible issues on my side.
Any insights or ideas would be appreciated. Thanks!
Regards,
Joseph