A couple of customers have recently contacted us about problems with Outlook 2011 for Mac when it’s configured to make SSL connections.
Outlook 2011 for Mac has a bug: It tries to use the long-obsolete “SSLv2” protocol that is no longer supported on modern mail servers, including ours. If your network also uses a very common kind of firewall that prevents “client-initiated SSL/TLS session renegotiation”, SSL connections will simply fail.
The best solution to this is to upgrade to a modern version of Outlook. Outlook 2016 for Mac, for example, doesn’t have this problem.