1. DAG Active Manager Check
2. Mailbox Database Status
3. Dag mailbox database backup status
4. Mailflow test report
5. Mail queue status
If you want you can schedule it in task manager and you will have health check report emailed.
This is going to reduce some effort from the system administrators head and alert you on time to prevent a major issue.
Download link:
https://gallery.technet.microsoft.com/Exchange-2013-DAG-and-5f9dad03/file/138540/1/Exchange%202013%20DAG%20Health%20Check.ps1
Exaustive and original Microsoft Article:
https://gallery.technet.microsoft.com/Exchange-2013-DAG-and-5f9dad03
Other article
http://msexchangeguru.com/2015/06/05/e2013-health-check-script/
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