IMAP Server utilizing high percentage of CPU

[PoorAdmin]

I am running EV 11.01 CHF4 we have IMAP server configure with only about 5 users. Every day I get alerts that the EV server is running at 100% CPU. When I check the server it's usually the IMAP Server service running at about 90%. I don't quite understand this for 5 users why would it consume so CPU? I have not run a trace yet but I will. I'm curious to see if anyone else has seen this behavior.

[JimmyNeutron]

Have you ran deployment scanner to see if your server is set to best practice? 

[PoorAdmin]

Not recently. The last time I believe was maybe 4-5 months ago. I don't think that anything has changed,, but I'll give it a try.

[AndrewB]

are your archiving tasks or indexing task running during the time the high cpu is experienced?