KB:You unexpectedly lose the ability to send eimail messages on a Windows Mobile 6.1-based device.

Microsoft has posted a temporary fix regarding the issue in the title above. Note that Exchange-based email accounts are affected, only POP3 or IMAP. Read the KB article from http://support.microsoft.com/kb/958639/en-us

Microsoft, I believe this is an opportunity to test Windows Update on our devices. Get a .cab file ready for a permanent fix and send it over the air.

A cab file that fixes this problem is available on Tracy and Matt's Blog:

Http://tracyandmatt.co.uk/blogs/index.php/2008/10/15/windows-mobile-smtp-fix