I have an issue with the email notification system. It has been working for about half a year now without any issue (and I didnt change anything), but since yesterday I start getting "error messages".
When I try a test mail out of openmediavault, it says "Email succesfully send", but I receive this:
Subject: undelivered mail returned to sender [openmediavault]
This is the mail system at host openmediavault.localdomain.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<receiving emailadress>: host smtp.web.de[126.96.36.199] said:
550-Requested action not taken: mailbox unavailable 550 Sender address is
not allowed. (in reply to MAIL FROM command)
Reporting-MTA: dns; openmediavault.localdomain
X-Postfix-Sender: rfc822; email@example.com
Arrival-Date: Tue, 26 Jan 2016 18:46:05 +0100 (CET)
Remote-MTA: dns; smtp.web.de
Diagnostic-Code: smtp; 550-Requested action not taken: mailbox unavailable 550
Sender address is not allowed.
Test message from openmediavaultVon:
This is an automatically generated mail message from the system notification service running on openmediavault.
Funny enough: I do get the email on the desired receipientadress (no idea how this works...) How can I debug this? Does anyone have any idea why this is happening?
edit: I would guess web.de changes something - but I think others are using web.de too, and I am the only one having issue - right?