[eghri]

It would be great if Gmail could provide a small notice on whether the email(s) you are sending to will be encrypted or not (just like the lock for HTTPS). I will probably still send the unencrypted email in most cases, but it would make you reconsider putting too much personal information in the email.

[mseebach]

There's very little utility for the enduser, and a lot of confusion to be had for all but the very most technical users.

Just because the inbound server uses TLS, it doesn't mean that the IMAP/POP server servicing the recipient does. He might very well download his email unencrypted on Starbucks wifi, and you're none the wiser for it.

The bits of the internet closest to the users are the ones most critical to secure. The backhaul between gmail.com and outlook.com should be encrypted (and is, so that's good), but it's very much a secondary concern to securing the enduser connections.

[magicalist]

What? The connection between gmail.com and outlook.com is exactly what the GP is talking about.

I agree that user confusion might result in a false sense of security, but it's ridiculous to assert that because there may be other weak links that "there's very little utility" to ensuring that email is sent over an encrypted connection between servers. In fact you could make the same claim about the TLS lock icon in the browser, as all you know is you have a secure connection to that server, you have no idea how they're actually treating the data you send to them.

I like the GP's idea. Have a little secure red/green based on an attempt to negotiate a connection with the destination server(s) while you're writing the email, then, if the server says it supports encryption, only send the email over an encrypted connection, else show an error message of some sort. Not for all users at first, maybe, but SMTP over TLS is obviously getting common enough now that it should be more or less required soon.