Hi,

It looks like there is a sort of bug in mml2015-epg-encrypt at line
1117.

http://git.gnus.org/cgit/gnus.git/tree/lisp/mml2015.el?id=6e422932976e94d6dbb7ad602c5be3eb481fe46c#n1117)

The whole form that begins at line 1113 converts list of recipients
provided as email addresses, key IDs or anything gpg can digest into epg
"objects". Unfortunately there is one corner case that makes this code
fail. That is when a key is valid but a uid on it has been revoked.

Let's follow the code. epg-list-keys returns all keys for an ID. That
seems correct, however, since it knows the uid we are looking for it
might check if the uid hasn't been revoked. mml2015-epg-find-usable-key,
on the other hand, knows nothing about the recipient, it just checks
validity of the *keys* not uids.

epg.el is a part of emacs, mml2015.el belongs to gnus. IMHO it is
mml2015-epg-find-usable-key that should be fixed. The function should
accept and additional (optional?) parameter with a recipient uid as
passed to epg-list-keys and reject keys with all uids matching the
recipient parameter revoked.

I'd like to know opinion of someone who knows better than I the ideas
behind this code.

-- 
Miłego dnia,
Łukasz Stelmach