Sending as another user using mail aliases

I’ve two users, let’s call them “userA” and “userB”. Both users are using WebApp. UserA should be able to send as userB. This is a no-brainer. Do the configuration on the ldap server, check with “kopano-admin --list-sendas userB” and everything works as expected.

Now for the tricky part: What if userB has some aliases (LDAP attribute: mailAlternativeAddress) configured (user_b@domain, b@domain, etc). UserA wants to send an email as userB but instead of using the primery address (userB@domain), userA wants to use one of these aliases (i.e. b@domain) as the sender address. This doesn’t work.

Everytime userA is trying to send this email, he get’s the following error message:

Unfortunately, I was unable to deliver your mail.
The error given was:

You are not allowed to send as user or group Info Mittelstandstag

You may need to contact your e-mail administrator to solve this problem.

So, the question is: how do I configure this?

Hi Timo,

just as a hunch, can userb sendas one of his aliases?

Honestly I would not use the address as an alias, if I wanted to have other people sending with it as well. I would recommend to use a shared store instead for this.

Fun Fact: userB is some kind of shared store with several aliases (info@domain, registration@domain, …). UserA want’s to send some mails as info@domain and some others as registration@domain and so on…