Why do email drop-downs show "email protected"
I believe this is something external to civicrm. Services like CloudFlare can cause email addressed to be 'protected'  and the fact you are saying this happens on https but not http seems to be another pointer in that direction.

You might want to consider this article: https://support.cloudflare.com/hc/en-us/articles/200170016-What-is-Email-Address-Obfuscation- or the one suggested by Michael https://blog.cloudflare.com/introducing-scrapeshield-discover-defend-dete/