I never thought the day would come when I would say this, but -- I hate GMail! It seems that the GMail guys recently made lots of adjustments on their system to prevent spammers from taking advantage of their resources. But in the process, it has affected a lot of users including myself.
For the past 3 days, almost all my outgoing mail is being tagged as spam and is bounced back to me. I can receive incoming email without problems, but I can hardly reply to any of them. And the worst part is, after so many failed attempts in a day, my account got locked up for 24 hours!
So now I installed Mozilla Thunderbird and just configured it for IMAP with my GMail account. Then for my SMTP server, I just pointed it to Mozcom's SMTP so I can send out email. Its taking forever to synchronize the mailboxes though since I've been using GMail for years.