POP/IMAP not fetching emails (Exchange 2010)

Configs as per screenshots below..

Neither IMAP/SSL, IMAP, POP3/SSL or POP3 email fetching not working.

I've successfully connected (using openssl) to the exchange server on 993/995 etc. from the host ost is running on with no problems, so am confident that the exchange end is set up correctly.

When I configured the email address/connectivity in ost, it reported no errors. I tested it with incorrect user credentials and it indeed did report the error correctly, so again am confident that the configs are right.

Am I missing some sort of "Master Switch" to turn on this feature, other than the ne in the email configs and the settings/email section?

Thanks in anticipation.