I am having the same issue with our host, Namesecure. They have repeatedly said they added the records accordingly, but the validation is still failing at the SRV record. It's been a week since they made the change so it would have propagated already. I can't see the SRV record or how it's entered but they have sent me screenshots to prove it's been entered. It looks correct but still does not validate. @ Vince, We’ve also sent you a private message to collect your custom domain, please click “ Private message ” at the upper right corner of the forum to respond to it, so we can further check the SRV records for it. Thanks for your cooperation. Best Regards, Eddy Li @ Vince, I understand you’ve spent two weeks on the SRV records setup with your DNS hosting provider. We appreciate your time and efforts. After doing a DNS query, we can find the SIP SRV record for Lync web conferencing (Protocol: _tls). But the SIP SRV record for Lync federation (Protocol: _tcp) cannot be found in our internal database. Since your situation is a bit different from Dave’s, could you generate a new thread in our forum to get dedicated support regarding the issue and avoid confusion? And it would be nice if you could provide us with the screenshots of the SRV records created at your DNS hosting provider in the new thread. To upload the screenshot, please click Use rich Formatting in the new thread and select Insert Image . Best Regards, Eddy Li