This sort of thing really pisses me off. Why the **** would anyone want to start encrypting *everything*? I have a mail server that sends out automated non-sensitive messages (*not* spam), and I foresee lots of pointless dicking about coming up. Consider:
1 - Google is a prime mover behind 'TLS Everywhere';
2 - Google charges for TLS on inbound connections;
3 - Google is behind 'Let's Encrypt', which issues free TLS certificates, which are trivial to get (I have one myself, and I did the whole thing online in a few minutes, with no human intervention);
4 - The Let's Encrypt certificate proves exactly nothing except that I have control of the server for which the certificate was granted (I only had to post stuff on it to get the certificate);
5 - Phishers control their own servers anyway, so can trivially get their own certificates. There is *no* "protection".
6 - If you really want private email, you wouldn't do anything as stupid as attempting to encrypt the connection - you'd encrypt the *email*
7 - the whole point of SPF records is to make sure that the email came from whoever it claims to have come from, and webmail providers do a good job of SPF validation. This adds exactly nothing
8 - Conclusion: this is all about Google trying to make money.
The only reason I had to get a certificate was because some pointless retards who run a public, non-sensitive and non-commercial website (ie. most sites) which I need automated access to decided to take TLS-only connections. Why?
I also run mailing lists where about 30% of recipients have gmail accounts, and another 35% have Microsoft webmail accounts. The emails are opt-in, non-commercial, non-spam, and are SPF- and DKIM-signed. About once a year Microsoft will silently cut off all outlook/live/hotmail/msn recipients, and I have to dick about for a day with some retard at Microsoft to get them re-enabled. I now suggest to new subscribers that they don't use Microsoft accounts. This never happens on gmail, aol, gmx/whatever. If Google starts popping up warnings for recipients who happen to be on gmail, they'll get the same treatment.