Email scanning should be turned off in any anti-virus. Also exclude EML
files from the scan. It provides no protection not provided by the regular
resident protection.
Besides that, McAfee and Norton are not compatible with Windows Mail and
Outlook Express and should be uninstalled. The latest version of Trend's
anti-virus seems to be causing problems too.
Click on Tools, then Options, then Send. If there is no checkmark in the
box before Send messages immediately, click on this box, then Apply.
Click on OK.