Can't send mails to support@

NethServer Version: 7.7.1908
Module: Mailserver


I now have a nethserver mailserver mailserver set up and it’s working almost perfectly , however I have one internal address (collected by a groupware support program) support@domian.tld that cannot be mailed internally

I get a message:

"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

<sysadmin@domain.tld> (expanded from <support@domain.tld>): host

MAILSERVER.domain.tld[/var/run/dovecot/lmtp] said: 550 5.1.1

<sysadmin@domain.tld> User doesn’t exist: sysadmin@domain.tld (in

reply to RCPT TO command)

Is this because the address is support and it’s being automatically redirected to sysadmin (a valid separate mailing list in my setup) and if so is there anything I can do about that?

Check if they exist in the e-smith database:


db accounts show sysadmin@


support doesn’t but sysadmin does as a psuedonym, (that I created) with two internal and one external address.



Ok it’s a bit messy but I can make this work by adding support@ as an external address as per this post:

but I don;t think this would work in all cases and also it is a lot slower for mail to be routed as it has to go via external servers so I’d still prefer to add an exception to dovecot if possible.

If not I can live with the delay now it’s working.

This also applies to “sales@” and “marketing@”, I still think it must be built in behaviour somewhere but surely it should be possible to turn that off without bypassing the internal routing?

Why broke something that’s working correctly?

I take your point, I just like to understand things like this if I can and find it annoying when I can’t find an explanation :wink:

Well, try to be like a mail server: dumb.
A mailserver is not “smart”, it does what it’s program and settings combined are telling it to do.
So if you ask to your mailserver "put this message into somebox@someserver" it’ll search the server.
If that someserver is the server you’re asking to deliver messages, it will ask itself "how can i manage messages for somebox?
List is quite short

  • there’s a mailbox, so it will deliver it to the right mailbox.
  • there’s an alias, so it will deliver the message to the box with that alias
  • there’s a distribution list, so it will deliver a copy of the message for every address into this list
  • there’s a forward addres, so it will send the message to another server
  • when everything fails, only if there’s a catchall mailbox it will put message into the pit of desperation and useless… the catchall mailbox. My suggestion is “never use a catchall unless overwhelming well paid”.

Otherwise, the answer is the same “hey buddy, no way to deliver it, sorry”, with the reason why it can’t deliver it.