Outlook 2002 and Exchange 5.5 SP4

[Mike Dorr]

I have four branches connected via a SonicWall VPN (mesh).
Two of the three branches can connect to their exchange
mailboxes, the forth gets permission errors. "Unable to
expand the folder. The set of folders could not be opened.
You do not have permission to log on." Two users/computers
in this fourth branch can access their mailboxes. These
are older systems compared to the others. All branches are
set up exactly the same, including the firewalls. The
users do not log on to the domain, though their computers
are joined to the domain. If I log them on to the domain,
it's a very slow process, but they can open their mailbox.
I would keep it this way but the VPN connections are not
100%. I just wanted to know if I'm missing something?
I can resolve the mailbox names under the Exchange set up,
but no access to the mailbox. It seems the local user is
not passing authentication to the mail server, but I can
access this server through Explorer without being prompted
for credentials.

 

[Mike Dorr]

I found that if I set the "Log On Network Security"
to "None" in the Exchange profile properties, I get
prompted for a username, password & domain and this will
work. Everytime! So, it seems my credentials are not
passing to the Exchnage server. Any way around this?