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 
Well, I do not think MIAb could handle them?
