Obscure e-mail problem

["m_surgenor" <malcolm@xxxxxxxxxxxx>]

I have a web application (the web access side of my mail server -
WorkGroupMail) which was working perfectly under MS Windows 2000
Server IIS4 but which is giving me problems since I upgraded my mail
server to MS Windows 2003 Server and IIS6.

I was pretty sure the problem was security related as basically I can
login, see all the headers of the e-mails in the webmail inbox but if
I select one of the e-mails it opens it but the content is blank.
The application should go and get e-mail from an .eml file. I also
can't delete any e-mails.

To test the problem I've opened right up the security and shares for
the user, the folders and the web but the problem remains.

But then I noticed there are certain times when it works perfectly!
I was away yesterday and tried it out remotely and twice during the
day I could read and delete my e-mails.  This happened at two
separate times and in between times it didn't work - and of course as
I was away from home there were no changes to the server in the
meantime.

I'm working with WorkGroupMail support to try and resolve this but
can anyone else think of a source for the intermittency?  Are there
any logs within Windows 2003 Server that show connections or access
that I could look at? Clutching at straws - are there any timing
restrictions that could have been set on the server?

TIA

Malcolm