Symantec Email Proxy error 1003 9

Nearly every time I tried to send an email message I would get this error (Symantec Email Proxy error 1003 9) on both of my PCs, one was using MS Outlook, the other was using MS Outlook Express.

I made a setting change in Outlook and Outlook Express that has eliminated my problem on both PCs.

Under the email "Account" settings I checked the box for "This server requires a secure connection (SSL)".

I made this change on both PCs about a week ago, and both have sent messages perfectly since that time.