In one fresh install of Exchange 2013 with Windows 2012 I have problem with 19 clients that have Access in one mailbox via Imap. Some of this clients(randomly) sometimes, have problem with authorization.
I make this change ttp://technet.microsoft.com/en-us/library/ff477612%28v=exchg.141%29.aspx in registry
and put Maximum Allowed Sessions Per User 30
and in ecp Servers->"ServerName"->Imap4->More Options...-> Maximum connections from a single user: I put 30 but with no luck
My Server give me this event
Log Name: Application
Source: MSExchangeIS
Date: 24/9/2014 9:41:03 πμ
Event ID: 9646
Task Category: MAPI
Level: Error
Keywords: Classic
User: N/A
Computer: xxxxxxxxxxxxxxxx
Description:
Mapi session /o=xxxxxxx/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=2fe5200f85644a77ae4b3f8f0af07e8f-xxxxxxxx with client type PopImap exceeded the maximum of 16 objects of type Session.