KEMP LoadMaster was configured to terminate SSL connection on the load balancer and the connection to the Exchange servers was encrypted as well. Recently, I came across a case where Mac’s built-in Mail client would not connect to Exchange through KEMP load balancer that was configured to user Layer 7 load balancing on KEMP LoadMaster. Charm-box blog on deviantart shimeji for mac. Today I set up webmail in my Microsoft Office 365 subscription on my Mac. Worked fine all day. Connection to server failed or was dropped error message. Trying to figure out what. Airmail got them, and Outlook didn't. Any idea why this is.

You need to make sure your OutlookAnywhere and AutoDiscover settings are setup properly along with split-dns.

Please provide the output from the following commands so that we can check to make sure your settings are set up correctly.

Also, make sure your OWA URL resolves externally to your external IP and resolves internally to your internal IP. Make sure you also do the same for autodiscover.domain.com. The easiest way to do this is to create a DNS Zone for mail.domain.com (assuming that is your OWA URL) and then create a blank A Record and point it to your internal IP Address for your mail server. Then create another DNS Zone for autodiscover.domain.com and create a blank A record and point it to the internal IP Address of your mail server. Then check your external DNS records and make sure mail.domain.com and autodiscover.domain.com point to your external IP Address of your mail server.

The next thing to check is the Virtual Directories and fix them accordingly too. They should all be mail.domain.com (assuming mail.domain.com is the OWA URL that you chose).

If some of these Exchange PowerShell commands error out, don't worry, these are to provide everything from Exchange 2013 back to 2007.