Reactivate a broken IMAP service on Microsoft Exchange 2013/2016

And one day, suddenly, IMAP service stopped working properly on my Exchange 2013 mail server.

Usually by telneting to imap port, exchange server returns a banner.


When the IMAP service is broken, the telnet screen is blank and the connection aborts. The initial idea to restart the IMAP services on the exchange does not fix the problem. (In this case all the exchange roles reside on the same server)


Run the following command on a powershell window

Get-HealthReport <servername>  | where { $_.state -eq “Offline”}

It will return an offline IMAP.Proxy healthstate.


Usually this is a Microsoft bug, since it appears after installing a Cumulative Update on the Exchange Server. By setting online the IMAPProxy, the IMAP service comes into life. Run the following command:

Set-ServerComponentState -Identity <servername> -Component IMAPProxy -State Active -Requester HealthAPI


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