Mail reception on a PDA

Does anybody know how to set up Messaging [on a Fujitsu-Siemens Loox 720
running Windows PPC 2003] when the username/password are different for
sending and receiving?


I have a BT broadband account with an add-on e-mail account from Plusnet.
For receipt one logs on using the mailbox name (eg ctwatts+chris) and
password.
For sending one logs on using the account name (eg ctwatts) and password.
[That is not a problem with Outlook Express etc on a desktop as this is
specifically catered for]

This is not a problem on the PDA when using the root mailbox (ctwatts) as
this has the same parameters for both sending and receiving. But for any
other mailbox then you can receive but not authenticate for sending as the
parameters differ.

Suggestions/solutions would be welcome.

TIA
Chris