How to solve the Could not establish trust relationship for the SSL/TLS secure channel error

Last update:
Created :
Written by Thomas Speekenbrink

Overview:

If you are using the Nebula Synchronizer and aren't able to continue past step 2 due to the following error:

Unable to connect to Microsoft Exchange. Please verify your settings.

The request failed. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

How to:

This error message is shown if something is the matter with the SSL certificate of your email domain / email server. It might probably have been expired or a self signed certificate is being used, which is not supported when using the Nebula Synchronizer.

Contact your local IT party / system administrator to solve this issue.