Google Apps - Too many simultaneous connections error18 Jul 2009
Somtimes Google would lock your IMAP account due to too many authentication tries using wrong password or too many IMAP simultaneous connections. I have not been able to figure out a solution to unlock it.
What I noticed, it gets unlocked after five days, yeah that's right you would have to use webmail for those days. It's also important to make sure, your email clients have right passwords otherwise they would keep making requests and getting IMAP locked.