We have installed file server and Domain on windows 2003 R2 SP2. All user have joined and all MAP ready for store DATA and E-mail.
may 1 month a go We don't know why. there are sometime clients when they START open outlook(2003,2007), the outlook can't fine or access DENIED on the file stored in map drive. but folder map drive can access to file normal when explore on it. But when we try use remote desktop to remote to file server or DC until it was connect and then outlook work and can access normal.
I really don know what something occur with my server and remote desktop with mail client that access file on file server.

For security use Bit defender license in network
Windows 2003 Standard Edition license

Thank you for your interesting and help.hi
in general its not recommended to install file server service with domain controller on the same server!
for best practice you need to get new server for the file server

for now u need to check is there windows update installed recently and disable the bitdefender then test your outlook
and u need to check the services..
Thank for your REPLY and interesting.
yes for checking update on server is  check option Let me choose when to install them.

It not sure for generate this issue.  I have noted and analyzed on remote desktop if it connect smooth to server may not no any PC occur even though.
but if not i will occur or generate on client for E-mail accessing denied to folder store the server.

And what kind of service that i should point to check.