Exchange SMTP and POP accounts

[Cam474]

Hi,
I need to be able to enforce users POP email account as the default account.
I can set it as default, but as soon as the user logs off or restarts it
reverts back to the exchange account.
The clients are configured to use an exchange mailbox for centralised
storage and recovery, but the original public domain setup in exchange no
longer exists.
So if the users do not change to POP as default and send out using SMTP the
mail never goes anywhere as the public domain does not exist.

Thanks
Cameron