Lync and Exchange Web Services Over HTTP

Spoiler: It doesn’t work.

The behavior you’ll see is that the Lync client will issue the Autodiscover query, receive a successful response, and then never even attempt to contact the EWS URL. No DNS lookup, no HTTP request, nada. Consequently you’ll see “EWS not deployed” in the configuration info or get the red bangs on the conversation history and phone tabs.

The only fix available is to modify your EWS virtual directory URLs to be HTTPS instead of HTTP, which you probably should be doing anyway, but I have run across deployments where this was not the case. After the change to HTTPS the Lync client will begin contacting the EWS URL correctly.


Recent content I've written for you—just for you!— to enjoy while you're here.


Quick commentary and links to other sources you'll find interesting. I promise.


Some personal background, links to related projects, and other ways to connect.

Hi there. My name is Tom Pacyk and this is my small home on the web. I love the intersection of design, technology, and communication, which is a combination that led me to a career in sales and marketing roles at places like Zoom and ServiceNow. They're a bit old now, but I also had the opportunity to publish a couple of books along the way.

Portland, Oregon is home for me, my wife Beth, and our three kids, but I'm actually a Midwestern transplant—I grew up in the Chicago suburbs and went to school at Purdue and Illinois. When I find some free time I'm probably going to concerts, rooting for the Portland Timbers, or working on my Sunshine Burn Photography project.