try reading the directions carefully from this link. hopefully they will help you.
Configuring The POP3 E-Mail Checker/How can I get the settings from Gmail?
http://www.msgplus.net/help_tutorials.php?tut=pop...-clients#pec-gmail
one of the points in the tutorial is this:
9. Click "More Options..." if you want to launch another program (mail client) or URL instead of gmail.com when you click a mail link in Plus!.
maybe you have enabled in those options - for gmail to be checked through outlook express
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