send mail as other user (alias)

[Jelle Langbroek]

Hi,

I've configured my Kolab account (my own server) in Thunderbird. Now
it's possible to send mail as a different user / alias as long as it's
in the same domain.
Example:
I'm user at domain.com
Another user has otheruser at domain.com and has alias o.user at domain.com
Now, I am able to configure an alias in Thunderbird for my account and
send mail as both otheruser at domain.com and o.user at domain.com.
I believe I should only be able to send mail as user at domain.com

Why is this?

Thanks.

Best regards,
- Jelle