No matter how I try to parse that it doesn't seem to make sense, neither as a straight reply, nor as satire/joke/irony.

Can you elaborate? Sorry if I'm being thick ...

They assume that you write your email on their web interface, to which you connect over https. and when they send your mail to anotjer server, they do so over a ssl encryption.

of course, if you use an email application, you can enable/disble ssl/tls if you wish to do so.

Ah, so I'd have to use webmail. I guess that makes sense, but it makes it impossible for my use cases.

Thanks for the clarification.