I've migrate most of mailbox (1500) to exchange 2013 from exchange 2007, recently one serious issue happens, can't send mails internal and external, after check log, find the event id 9646 as belows, I've tried to add "Maximum Allowed Sessions Per User" to registry but no use
Mapi session /o=eBaoTech/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=SHMBX01/cn=Microsoft System Attendant with client type Transport exceeded the maximum of 16 objects of type Session.
from below MSExchangeIS 9646 , no object type is 'Session', what the exact object type for our issue?
http://technet.microsoft.com/library/ff980641.aspx
please help me, a lot of thanks.