Event ID 15021 HttpEvent Exchange 2013

Recently a client of mine stopped receiving external emails, 2 days after their SSL had been renewed.
Event logs revealed error 15021 come from HttpEvent, stating "An error occurred while using SSL configuration for endpoint 0.0.0.0:444. The error status code is contained within the returned data."

Quick and easy fix.

• From an elevated command prompt, run netsh http show sslcert
• From the returned content, look for 127.0.0.1:443, and copy the certhash and appid details
• Run netsh http delete sslcert ipport:0.0.0.0:444
• Run netsh http add sslcert ipport=0.0.0.0:444 certhash=xxxxx appid="{xxxxx}"
• Once you've successfully added the 0.0.0.0:444 binding, reboot your exchange server, and all will be well.