I have a user that needs to access and send from multiple mailboxes but I am haivng a problem setting it up.
What I have done is setup a mailbox for the user then set Exchange to forward a copy of incoming mails from the other mailboxes to the users mailbox. All mails are received with out problem. The user is able to reply to mails that have been sent to the other mailboxes but is not able to send a new email. I have set Full Permissions and Send on Behalf of in mailbox properties and Send as permissions when right clicking the mailbox.