Exchange 2013 introduced a new process called Managed Availability which aims to monitor the health of various system resources. During installation, Exchange automatically creates several HealthMailbox objects in Active Directory which are used by the Managed Availability service to send email probes through Exchange to verify the mail flow every 5 minutes.

To prevent these emails from polluting the logs, ORF automatically detects these Health Mailboxes during installation and excludes these email probes from logging.

Possible Issues

The list of Health Mailboxes may change (e.g., when a new Mailbox Server is added to the organization) and probe email may start showing up in the ORF logs. To address this problem, ORF should be made aware of the newly created HealthMailbox objects. This can be achieved by using the ORF Exchange Helper (a command-line tool shipped with ORF).

Also, Exchange 2013 CU9 changed certain details of how health probe emails are handled, which broke the automatic recognition of these emails in ORF (see our blog post for details). ORF 5.4 shipped with an updated mechanism that restored the recognition capabilities of ORF.

Rediscovering Health Mailboxes

To update the exclusion list of Health Mailboxes, follow the steps below:

1. Start a command prompt as Administrator and navigate to the ORF directory (Program Files (x86)\ORF Fusion by default) where the ORF Exchange Helper executable (orfmexhelper.exe)resides.
2. Issue either of the following commands:
   orfmexhelper.exe -updatehealthmonitoring
   or
   orfmexhelper.exe -uhm
3. Restart the related Exchange services as instructed by the ORF Exchange Helper (MSExchangeTransport, or MSExchangeFrontEndTransport, or both services, depending on your setup).