I do not fully get it...

You suggest to toglle "Work off-line", but then my POP/SMTP will not work for sure (just like you mentioned).

In my case the Exchange server is not reachable in case I leave the office. I can perfectly be connected to "the Internet" without having access to exchange. I suppose that your Exchange server is publically available, correct?

I've followed the following strategy:
* Put Outlook off-line (PC remains connected to internet)
* Try to send a mail from the POP account


* Send it
* The mail now remains in my outbox, which is to be expected.
No message is shown at this moment, it is just put in outbox.
* Explicitely click on "Send & Receive". The mail now gets sent without problems.
* Toggle on-line
* Create a mail to another new address, still using the same POP account.
* Send it
* Now immediately the message comes that outlook needs to be connected in order to send.

:-(