2nd gpg colon field: i := invalid (e.g. due to a missing self-signature) Also add a comment that keys having the encrypt capability only on subkeys (i.e. not on the main key) are ignored. Which was always the case. Time for a rewrite maybe.. or just use the now long existing Mutt crypt_opportunistic_encrypt feature.
Generate mutt crypt_auto... send-hooks from gpg pubring.
A shell script using sed to parse the output of
gpg --list-keys --with-colons ... and generate a list of Mutt
send-hook "!~l ~t mail@example\\.org" "set crypt_autoencrypt crypt_autosign"
commands for each UID, discarding disabled, expired, invalid and revoked keys.
The latest version of this script is also downloadable here as it was always since the year 2008 ...