With Microsoft Exchange IMAP and Microsoft Exchange IMAP Backend services started the CPU utilization runs 99-100% full-time. If these services are stopped, the CPU utilization runs 8-45%. This issue seems to have begun when CU 11 was installed and .NET 4.6.1 was installed in error. .NET 4.6.1 was removed and .NET 4.5.2 was repaired and server restarted. Same issue. Installed CU 14 and .NET 4.5.2 is still the latest .NET installed. If the ServerComponentState for component ImapProxy state is Inactive the CPU % drops back to "normal" range. Once the ImapProxy state is Active the CPU goes back to 99-100%. The Exchange server is a VMware VM with (2) vCPU and 32GB memory running Windows Server 2012 R2 with the latest Windows updates. My voicemail system requires IMAP to integrate with Exchange. Any ideas were the bottleneck might be?