I want to check POP and IMAP mailboxes every 5 minutes for new mail.  Outlook
currently does this and puts an envelope icon in my systray when there is new
mail.

But, if I keep Outlook open all the time, it takes up a lot of ram (winword is
left open too since it is integrated somehow into outlook) and the network
backup can't ever backup the .PST file since it is always locked.

Is there a way to get the exact same functionality of checking mailboxes and
putting an envelope icon in the systray when there is new mail, but not having
to leave outlook fully locked and open all the time?  I would like to click
the envelope icon and it fully opens outlook, and afterwards outlook can be
kept semi-closed so the backup can run on an unlocked .pst file, but mail
checking continues.

There may be external utilities to do this but the ones i've seen don't seem
to support IMAP or don't integrate easily with outlook, or are too complex
(simple is better for the users I need this for, they are used to looking for
the systray icon as an indication of new mail).

Thanks for any pointers.