Inbound Mail Flow Stops to Exchange 2013 Server

Over the past couple of weeks, I have performed a few transitions to Exchange 2013 and each have had a similar issue with inbound mail flow stopping, both oddly enough with a Barracuda spam firewall at the front end.  The issue occurs when mail flow is transitioned from a legacy server to a new Exchange 2013 server where mail flows initially but comes to a complete halt (queued on the Barracuda) after you think all is good.  When the Barracuda is repointed to the legacy server, inbound mail flow resumes its normal function.

What I have found out, in these specific scenarios, is that the default receive connector on the Exchange 2013 server(s) has to be modified.  The default receive connector has an initial limit of 2% for inbound connections from a single IP address for the MaxInboundConnectionPercentagePerSource setting and an initial setting for MaxInboundConnectionPerSource of 100 connections from a single IP address.  Unless you anticipate a very small amount of inbound email, I recommended changing one of these two settings.

To resolve the issue in both cases, I set “MaxInboundConnectionPercentagePerSource” to 100 percent on the default receive connector of the Exchange 2013 server(s).  The command you will need to run from the Exchange Management Shell (EMS) on a 2013 server is…

  • Set-ReceiveConnector -MaxInboundConnectionPercentagePerSource 100

After this change, you can restart the 2013 transport service and repoint the Barracuda to the 2013 server to resume normal mail flow.

For additional information about Exchange 2013 message throttling and receive connector settings, refer to these two TechNet articles…

I am certain there are probably alternate resolutions, therefore I welcome your comments and suggestions.

Thanks and good luck.

Todd (@oddytee)


Simplify OWA URL for Exchange 2010

Here are several references to simplify the URL for OWA.

Redirecting OWA URLs in Exchange 2010…

Redirect OWA Exchange 2010 & Exchange 2013 – The Cool and Easy Method…

NOTE: As of 24 Sep 2013, URL redirection for OWA in Exchange 2013 does not work with the above steps or the MS TechNet article. For simplifying the Exchange 2013 OWA, click here.

Simplify the Outlook Web App URL…

Simplify the Outlook Web Access URL…

Simplify the Outlook Web App URL…

by Todd Nelson (@oddytee)

Room Lists in Exchange 2013

Creating room lists in Exchange 2010 has developed over time into a process that is fairly easy to implement and visually see (Recipient Configuration > Distribution Group).  However, Exchange 2013 is not quite there yet.

It is true with both Exchange 2010 and 2013 you have to create a room list via EMS.

With Exchange 2010, a distribution group can be converted to a room list…

     Set-DistributionGroup -Identity “West Coast Office” -RoomList

However, with Exchange 2013 CU1 (using the same command syntax), a distribution list cannot be converted to a room list…

     Set-DistributionGroup -Identity “East Coast Office” -RoomList

This is the error receive in the 2013 EMS…

Group “domain1.local/Test/East Coast Office” can’t be converted to a room list. Room lists can only have room mailboxes or room lists as members.
“domain1.local/Exchange Users/Test-Admin” is not a room mailbox or a room list.
    + CategoryInfo          : NotSpecified: (domain1.local/Test/East Coast Office:ADObjectId) [Set-DistributionGroup], TaskInvalidOperationException
    + FullyQualifiedErrorId : F25FFBB1,Microsoft.Exchange.Management.RecipientTasks.SetDistributionGroup
    + PSComputerName        : d1-ex13-01.domain1.local

In order to create a room list in Exchange 2013, we have to create a new distribution list as a room list from the very beginning.  Using EMS, we should be able to issue a command similar to the following to create our new room list…

     New-DistributionGroup -Name “East Coast Office” -OrganizationalUnit “domain1.local/Test” -RoomList

Upon successful creation, we will see that the request is completed with the details of the new room list displayed (Name, DisplayName, GroupType, PrimarySmtpAddress).

The biggest difference for me between 2010 and 2013, is that in 2010 we can see the room list (in EMC) after it has been created (or converted).  In 2013 CU1, room lists are not displayed in the EAC under Recipients > Groups–and they are nowhere to be found in the EAC.

But there is a way to confirm they have been created.  Use the following command to display all distribution groups and what type they are…

     Get-DistributionGroup | ft -auto Name, RecipientType, RecipientTypeDetails

Once we have confirmed the new room list has been created we can add members to it.

NOTE: We can only add room mailboxes (or other room lists) to room lists or we will receive an error message similar to this…

     “Only room mailbox or room list can be added into room list”

At this point, make sure you have a room mailbox to add to a room list.  Once you have identified your list of room mailboxes that will be added to your room list, use the following command to add room mailboxes as members of the room list…

     Add-DistributionGroupMember -Identity “East Coast Office” -Member

Use the same syntax to add other room mailboxes to your room list.

Now that we have created a room list and assigned room mailboxes to it, scheduling conference rooms for a specific location should be easy using the Office Outlook client or Exchange 2013 OWA.

Reference(s): Scheduling Meetings with Room Finder

by Todd Nelson