Problem

When launching Outlook 2016 on your Mac, you receive the following request to Verify Certificate:



You may also receive a similar request for connecting to 'adelaide.anglican.com.au'. In both cases, clicking 'Continue' allows you to proceed and Outlook will successfully connect to the server. However this can be an irritating problem.


Temporary Solution

  1. Click 'Show Certificate'

  2. Tick 'Always trust ".squarespace.com" when connecting to "adelaideanglicans.com" ' and click Continue

  3. Enter your local computer password when prompted and click 'Update Settings'




Cause

This is an issue caused by the Outlook 2016 looking for automatic configuration information, and the SSL certificates used by Squarespace to host our website.


Outlook 2016 looks in a number of places for an automatic configuration file, and one of these is an HTTPS URL of the domain it is trying to connect to. Squarespace (and Webfaction, the host of our old adelaide.anglican.com.au site) use an SSL certificate for their own domain to provide an HTTPS connection to hosted sites. Outlook correctly alerts the user that something possibly suspicious is going on, as a secure connection to adelaideanglicans.com uses a certificate from squarespace.com (or webfaction.com). In this instance we know the cause and can tell Outlook to trust the certificate.


A permanent solution will require us to find a way to secure the HTTPS connection to our website with our own SSL certificate.


Source

How the Autodiscover service works with Office 2016 for Mac

SSL certificate for website