I know the new version is about to released, but its wroth mentioning here:

Eg: Server A
On server A i have a domain called a.com

Server B
I have multiple domains including a.com BUT, a.com is disabled from the control panel.

Now the problem is, when the user@a.com from server A sends an email to a virtual domain hosted at Server B, this error occurs:
"Sender address rejected: not logged in"
Which simply means that "user" mailbox for domain a.com is not on this server BUT it seems to me like a bug as this should NOT happen when the domain is disabled.That's the whole point of disabling a domain !!!

The interesting thing is that, some domains which are disabled wouldn't give such error but a few do.

Any thoughts WHY ?