Hello Kel,
Unfortunately, currently Kentico works with POP3 only. The reason is that we found free 3rd party libraries for POP3, but no one for IMAP.
On the other hand, if you want functionality like this available in the feature version of Kentico, you can suggest it and also other users will be able to vote for it (more users = higher priority), on the special page:
Kentico UserVoice.
Best regards,
Martin Danko