Outlook 2003, Win 7 x64, Gmail. Outgoing fails. Incoming OK

Buggy problem that I cannot find any clues about.
I've setup this exact sort of thing before with no issues.
This account is using Centurytel as their DSL ISP, with a new dell system running windows 7 Pro x64, and a fresh intstall of MSO 2003.
Setup Outlook 2003 per the gmail instructions: imap for incoming, smtp for outgoing, set the server ports, ssl etc all correct, double checked, triple checked.

no outgoing mail has ever completed [its been a week now]. All incoming mail is fine. Outgoing mail fails whether its a "reply" or a newly-created message of any length, regardless of attachments or not. they land in the outbox, cannot send.
tried turning off the AV... no effect.

is there a firewall setting in Win7 Pro that could be affecting outgoing?

is it possible that we could limp along by changing the outgoing server to a centurytel server? that has some admin ramifications I realize, but might it work?

yep. as covered in my OP

well, it started working.... don't know why.
the only thing "different" was getting her to use a browser to login to gmail, check mail, settings, etc, then out. .....
went back to outlook, hit the "send receive" button and the outbox emptied a week's worth of constipation