Webapp: Sender address rejected: not owned by user

I would like to run Zulip, a Slack replacement (on a different server than MIAB). That webapp needs to send email to users. So I got zulip@abc.com. Which works fine.

But then they have a second noreply and when I try to send trom that I get the eror:

smtplib.SMTPRecipientsRefused: {'=?utf-8?b?54Os44OI?= <receiving@xyz.com>': (553, b'5.7.1 <noreply@abc.com>: Sender address rejected: not owned by user zulip@abc.com')}

I looked around the forum and the web, and tried a few things. Played around with creating different users and aliases, but to no avail.

Zulips email documentation is here: Outgoing email — Zulip 5.6 documentation

And this is some info from the Zulip email config file:

## The noreply address to be used as the sender for certain generated
## emails.  Messages sent to this address could contain sensitive user
## data and should not be delivered anywhere.  The default is
## e.g. noreply-{token}@zulip.example.com (if EXTERNAL_HOST is
## zulip.example.com).  There are potential security issues if you set
## ADD_TOKENS_TO_NOREPLY_ADDRESS=False to remove the token; see
## https://zulip.readthedocs.io/en/latest/production/email.html for details.
ADD_TOKENS_TO_NOREPLY_ADDRESS = False
## TOKENIZED_NOREPLY_EMAIL_ADDRESS = "noreply-{token}@abc.com"
## NOREPLY_EMAIL_ADDRESS is the sender for noreply emails that don't
## contain confirmation links (where the security problem fixed by
## ADD_TOKENS_TO_NOREPLY_ADDRESS does not exist), as well as for
## confirmation emails when ADD_TOKENS_TO_NOREPLY_ADDRESS=False.
NOREPLY_EMAIL_ADDRESS = "noreply@abc.com"

I turned tokens off for now, to deal with a different day :smile_cat: Well, I do not think MIAb could handle them?

PM me with a non-redacted version of this please. Redactions are making my brain explode today it seems.

Thank you for the offer to help. I have sent PM.

In the meanwhile, I manged to find a workaround by setting two email users (one zulip@abc.com and one noreply@abc.com) and they are each alias of each other and I manually allowed them to send as the other

Mail & Users

Aliases

Permitted Senders

I’ll enter the mail users that can send mail claiming to be from the alias address.


Added both and did that for each user email.

It feels a bit hacky though … :sweat_smile: