First, we have gotten a new SSL certificate from SwissSign which is our certificate authority (SwissSign is largely owned by the Swiss government). This new certificate allows for wildcards so subdomains like proton.me no longer throw invalid certificate errors, and there is no more certificate errors when using negotiating TLS connections with mail.proton.me.
Our end-to-end encryption model of course does not really rely on SSL, but having a certificate that supports subdomains does enhance the user experience.
We have also set up a dedicated security email address, email@example.com, for all security related issues. This way, we can better track security related queries and respond faster to them. firstname.lastname@example.org is meant for communicating with Proton Mail security contributors(new window) so we ask that you use email@example.com for other inquiries.
We are of course working day and night on improving Proton Mail so we can support more users. In the past week, we have doubled our server capacity and are now taking people off the waiting list daily. Thank you again for your support and patience!
P.S.: Regarding TLS 1.2, we will update to support this once we get our new servers.