Your organization may require all communication with Exchange web services to use TLS 1.2.  If you are getting an Exchange error "An existing connection was forcibly closed by the remote host" you may need to make registry modifications in order for Quicklaunch to use TLS 1.2.  

Follow these instructions:

Add the following registry entry on the failing PC, reboot it, and test.

Windows Registry Editor Version 5.00



Here is the Microsoft source article: