This article applies to:
Microsfot Windows Server 2016, Exchange Server 2016

You have multiple Exchange Servers in a cluster configuration and you need to check if your load balancer is equally distributing inboud SMTP traffic to all cluster members.

  1. Open Performance Monitor and Select the plus sign to add a new performance counter

2. Under Counters from Computer, select the Exchange server computer you want to monitor

3. Select MSExchangeFrontendTransportSMTPReceive group and click on the arrow right to it to see individual counters.

4. Select Inbound Messages Received /sec

5. Under Instances of Select Object select Total

6. Click Add

7. Click OK.

Repeat the steps 1-7 for every Exchange cluster member you want to monitor.
At the end you will get a graph similar to this one. In this one we can clearly see that Exchange server C2 is not receiving any SMTP traffic.

After the problem is corrected you will see traffic being distributed evenly like in the following graph:

You are experiencing an incoming mail flood and need to determine through which receive connector are the messages coming in.

Implement all the steps like we have shown in example 1, with exception of the last step, where you should select All Instances instead of Total. 

This will add an individual counter for every receive connector you have on that server. And accordingly, you will easily be able to determine through which connector the flood is coming in.