Exchange 2013: HealthMailbox is Appearing in SPAM Quarantine

After configuring Anti-Spam in Exchange 2013 (RTM or even with SP1) you can see thousands of transfers appearing in SPAM quarantine. Those spam items sent from inboundproxy@inboundproxy.com (or from inboundproxy@contoso.com).

Here is why it happens:
As you probably know, Exchange 2013 introduces a new feature called Managed Availability which performs system monitoring of various components of Exchange infrastructure and provides the ability to detect and recover from problems as soon as they occur. One of the tests Exchange Managed Availability performs is to send an “Inbound Proxy Probe” message once ever 5 minutes from an Exchange 2013 front end server to the backend server. If you have a multi-role server deployment, this proxy probe occurs locally on the Exchange 2013 server between the frontend mail service “Microsoft Exchange Frontend Transport” and the backend transport service “Microsoft Exchange Transport”. The purpose of this test is to ensure transport functionality is working as expected between these components.

This test however can be problematic and an issue is often seen by Exchange Administrators including:
In the event Content Filtering (Intelligent Message Filter) is configured on the Exchange 2013 backend with the install-AntispamAgents.ps1 script, Inbound Proxy Probe messages will be quarantined, rejected or deleted by the spam filtering engine.

Solution:
First of all, just in case, Download Engine and Definition Updates:
& $env:ExchangeInstallpathScriptsUpdate-MalwareFilteringServer.ps1 -Identity $env:ComputerName

Set BypassedSenders to address Microsoft’s “inboundproxy”. I’m adding two addresses here, for RTM version and most updated Exchange edition 🙂 :

Set-ContentFilterConfig -BypassedSenders inboundproxy@inboundproxy.com
Set-ContentFilterConfig -BypassedSenders inboundproxy@contoso.com

Feel free to contact me, or any other Best IT Experts in Canada to discuss this or any other IT related challenges you have in your business. Don’t forget to subscribe to our news letter.