I thought it would be pretty clever to automatically encrypt emails in my Gnus installation whenever all the addressees have a corresponding PGP key in my keyring. Defaulting to encryption whenever possible is the right thing ™ … theoretically. The practice:

And some more of the same kind. Of course people who use webmail frequently are unable to decrypt in general. And even the others seem to avoid the trouble to setup encryption again in their mail setup and feel unconfortable when receiving encrypted mails. So I won’t bother them anymore and give up on email encryption.