(Applies to Epicenter Server)

Problem:  When sending an update from an address list with thousands of contacts, you receive an error like one of these:

06/09/11 16:32:57 [All Users] Unable to load the table of contents for All Users.  "Microsoft Exchange Address Book" reported that, "The operation failed."
Reason: Unspecified error (0x80004005)

Solution:

Exchange 2010 and later versions will throttle busy connections. You need to turn off throttling for Epicenter Server  as follows:

1. On a computer that hosts the Microsoft Exchange Management Shell, open the Microsoft Exchange Management Shell.
2. Type the following commands. In the last command, change "Example" to be the account used by Epicenter Server.
   
   Exchange 2010
   New-ThrottlingPolicy EpicenterPolicy -RCAMAXConcurrency $null
   Set-Mailbox "Example" -ThrottlingPolicy EpicenterPolicy
   
   Exchange 2013 and later
   New-ThrottlingPolicy EpicenterPolicy -RCAMAXConcurrency Unlimited
   Set-Mailbox "Example" -ThrottlingPolicy EpicenterPolicy