Alan said:
IMAP can work. I use an earlier version of Outlook, and put the PST
file on a cloud drive. The one real drawback is that you can't work
from two locations at the same time. Not a problem in my
applications, travel computer and office computer.
The problem with putting the .pst across a network is catastrophic
closure of the file. When you lose your network connection to the
remote file, the file is not closed gracefully. It's slammed closed.
That can corrupt the .pst file. It may not [yet] have happened to you
but it's happened to many Outlook users that networked their PST file.
http://support.microsoft.com/kb/297019
http://blogs.technet.com/b/askperf/archive/2007/01/21/network-stored-pst-files-don-t-do-it.aspx
Hopefully your online file storage provider (probably a more accurate
description than "cloud") saves backups for you and also retains
multiple backups spanning several past backups. If your networked PST
file is not backed up, and after it gets corrupted because the file got
slammed closed with the loss of the network or session connect, you're
left with an unusable PST file and have lost all your e-mails, notes,
contacts, and other info in that corrupted PST file.