I may have found an answer here.
https://support.google.com/accounts/...yUnlockCaptcha
the password provided from that page has got me past the password request (for both IMAP and SMTP) and allowed me to receive (and possibly send - a test msg has disappeared from out box), but it's now synchronising subscribed folders (while still sending) and has been at it for quite some time and says it will be another 24 minutes doing it.