Automatic Login using MS Exchange, Windows Messaging, or Microsoft Outlook

From Support

Automatic Login using MS Exchange, Windows Messaging, or Microsoft Outlook

When attempting to use automatic login to MS Exchange, MS Outlook, or Windows 95/NT Messaging, the Exchange Profile Name should be entered for the Email User setting and the Email Password setting should be left blank. This is the only documented method of automatically logging into MS Exchange and starting a mail session without user intervention.