John
If you go to all the newsgroups that are connected with email clients like
Outlook,Outlook Express, Windows Mail,Windows Live Mail, Thunderbird and you name it
then you will find that OP's that post that they get double emails,cannot
send,cannot receive etc, etc are caused by Anti Virus suites scanning in and
outgoing emails. Most also say that they have used their AV to scan emails for years
and have never had issues are finding that when they run into a problem with the
client then most of the time it is because of the scanning.
The fix for all these issues are to disable the scanning feature of the AV suite.
By disabling the email scanning you are still protected and no bad stuff will come
through because your resident AV will always catch it.
Even Symantec say so.
Turning off e-mail scanning is safe. See:
Viral Irony: The Most Common Cause of Corruption.
http://www.microsoft.com/windows/IE/community/columns/filecorruption.mspx#EOAAC
And this is from Symantec, but applies to all anti-virus programs.
From:
http://snipurl.com/bmf6
Is my computer still protected against viruses if I disable Email Scanning?
Disabling Email Scanning does not leave you unprotected against viruses that
are distributed as email attachments. Norton AntiVirus Auto-Protect scans
incoming files as they are saved to your hard drive, including email and
email attachments. Email Scanning is just another layer on top of this. To
make sure that Auto-Protect is providing the maximum protection, keep
Auto-Protect enabled and run LiveUpdate regularly to ensure that you have
the most recent virus definitions.