I'm experiencing the problem described here, in Outlook 2007 with Google Apps IMAP:
http://mail.google.com/support/bin/answer.py?answer=97150&topic=12816
The thing is, I have no idea how the connections might have maxed out. The account in question is set up on two computers and one iPhone. If the maximum simultaneous connections is 10, I don't know how it was reached.
Also, does anybody know how long this may last for? I'm unsure whether your account gets 'locked down' for some predetermined length of time, or should be available again once the number of connections has dipped below the limit.
So far the problem has persisted for 2 days.
Thanks for your help.