Outlook 2010 and 2013 have a realy nasty bug.
The effect when connected to a exchange server shows up in the inability to send out emails.
Incomming mails in cached mode just work fine, and outlook tells us in the status bar "Connected to server".
When you write a mail, it just gets stuck in the outbox and tells us about a communication error with error code 0x8004011D, meaning that the server is not available.
Just plain rubish, otherwise we would not have incomming mails and in the status bar it would not show "Connected to server"
When you create a new profile for the user, it works a few days, until again it blocks at this point.
When you create a profile without cached mode, it will work with no problems as well, but that's not the intention to have a cached mode.
The solution to this mistery are linked mailboxes.
When you create a profile and add the linked mailboxes as independent account's in outlook, you will get in troubles. It looks like outlook internally adds the linked mailboxes to the profile too, and then has double accounts and messes up things.
The solution is simple: Just remove the additional mailboxes from the outlook profile and mails will be sent out just as you would expect.