Question : Cross Domain Exchange Mailbox Access

Hi
I have granted a user from another AD full access to one of the mailboxes domain b. we have full trusts in place and operational so that not a problem.
The user from domani can setup the outlook profile no problem and access the mailbox and do whatever they want to that mailbox but they cannot send mail from it.
If the user tries to send email it says "you do not have permission to send to this recipient"

Any ideas?

Answer : Cross Domain Exchange Mailbox Access

If you delete the domainA account then the mailbox will be disconnected and no one will be able to access it.

It would be better for you to export the mailbox and recreate it in DomainB. If domain A and Domain B are in the same forest then you can disconnect the mailbox from the domain A account and reconnect it to an account in Domain B.