Exchange 2010 – Client Connection Issues

February 4, 2014

A while back I got a lot of complaints coming in from all over the place, regarding client connection issues. Where clients who logged in early in the morning where able to log in and others where not ? Sad smile

Interesting challenge. But since we are servicing a multi Timezone user base across the world. The heat was rising.

So first I thought it would be a client / internet connectivity related issue. But I was wrong.

After Googling a bit I found out that our parameters on the server where not set optimal when added more and more users and email domains to Exchange 2010.

So here is the solution :

Open the EMC and go to the server properties. Next to the LIMIT tab.


Change the Maximum Concurrent outbound Settings (and per Domain) to a more relevant number. Default it is 1000 and 20.

You will need to restart the Exchange Transport service when finished modifying these settings.

Also check the HUB Transport Global Settings – Max number of Recipients


More info you can find using Powershell to get hold of the ThrottlingPolicy Settings


if(!(Get-PSSnapin | 
    Where-Object { `

    $ -eq "Microsoft.Exchange.Management.PowerShell.E2010"})) {
      ADD-PSSnapin Microsoft.Exchange.Management.PowerShell.E2010

Hope it can help solving your mysteries Winking smile