Unable to access email folders. You must connect to Microsoft Exch

[tmac]

I have 10-15 users in my org that are receiving the following error:

"Unable to open your default e-mail folders. You must connect to your
Microsoft Exchange server computer with the current profile before you can
synchronize your folders with your offline folder file"

We migrated to Outlook 2007 about 2 months ago and since then this problem
is happening more and more. It is not happening to every person in the org
and is intermittant for others. For example one user can logon at a
workstation and get this error. Then go back to their own workstation and
access outlook 2007 with no problems.

This issue has been posted on hundreds of other forums with no resolution.
Seems to be a widespread issue yet there is no information on here.

 

[tmac]

Oh I forgot to add when one of these users gets this error message a new OST
gets created in the Local Settings\Application Data\Microsoft\Outlook folder.
Even if there is an existing OST file in there. The new file is always named
"Outlook0.ost"