If you're using Google App Engine to host your app, with a Custom Domain + SSL Certificate, and are experiencing SSL Handshake issues when Alexa tries to reach your endpoint - set your Alexa App Endpoint to the underlying App Engine path: https:// .
appspot.com e.g. if your Google App Engine App ID is my-app-1, then your Alexa App Endpoint will look like:
https://my-app-1.appspot.com/path/to/alexa/app Forum user freebusy suggested that it might have something to do with SNI:
https://forums.developer.amazon.com/forums/thread.jspa?threadID=5199 ...but until we get official word from Amazon, the above fix should get you running with App Engine + SSL.
It looks like the same issue I had (the link you mentioned) If you point your app to https://[something].
appspot.com you'll be using the appspot wildcard SSL certificate. Since wildcards certs are not allowed for production apps, you won't be able to publish your app until you find a solution. I had issues with Openshift (which relied on SNI) and Cloudflare (also relied on SNI). I finally moved everything over to Elastic beanstalk which does not rely on SNI and it works. If you're looking for a good SSL report that tests the cert on non-SNI connections:
https://www.ssllabs.com/ssltest/ [b]It would be great to get an official response from Amazon on SNI support.[/b] It really seems odd to me that it's not supported.