Hi.
I recently did some tests to determine for sure if the email server is rejecting emails after meeting the mailbox's quota.
I noticed in the email logs that the message is being deleted in cases where the mailbox has met the quota.
The issue is that in these cases, the email system sends an email from "MAILER-DAEMON@<emailhostname.com>" notifying the sender about the mail not being delivered. A similar email is also sent when the mailbox is not found in the system.
These emails are going through the smarthost (mailbaby in my case) and are being marked as spam, so they're not getting delivered to the sender. But I think that even if I disable the smarthost, the emails wouldn't be authenticated correctly before going out (SPF/DKIM, etc.), so essentially the email server would be delivering spam and being marked in a blacklist.
- Is there a way to correctly authenticate/sign this domain, so system generated emails can get to the destination?.
- Or in any case, a way to change the domain is going out from? For example MAILER-DAEMON@<mydomain.com> instead of the full hostname.
