Topic: Mail alias / SMTP AUTH problem ?
==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.2
- Deployed with iRedMail Easy or the downloadable installer? installer
- Linux/BSD distribution name and version: Ubuntu 22.04.2 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
[ I have used fake mail and domain names for now, can share the actual messages and domains involved if need be ;-) )
I have configured a VPS I rent where I installed iRedMail. It handles mail for my domain, 'domain.be'. My main mailaddress there is firstname.lastname@example.org. I can send and receive mails without problems, from various clients, all working well and quite easy to setup.
I have a domain at Gandi.net (other.be) that allows me to install mail aliases. I have configured one 'email@example.com' that points to 'firstname.lastname@example.org'. To be clear, this has nothing to do with my server setup.
My problem is that when I sent a mail from email@example.com (my mail server) to firstname.lastname@example.org (on Gandi) it never arrives and I eventually get an 'undelivered mail' message back from gandi that it couldn't deliver to the email@example.com. domain.be has spf, dmarc and dkim set up that all pass, and only SMTP AUTH is used so not sure where the error message comes from.
This is the mail system at host mslow1.mail.gandi.net.
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
<firstname.lastname@example.org>: host domain.be[x.y.z.w] said: 554 5.7.1
<email@example.com>: Recipient address rejected: SMTP AUTH is required for
users under this sender domain (in reply to RCPT TO command)
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