| How about code that goes out & fetches keys upon demand, al-la DNS?
That's what the next generation of Distributed Key Server stuff will do.
This works with procmail to get keys for all mail I receive.
As you say, fetching keys for all keys you ever receive will cause your keyring to become excessive ... I prefer to be able to fetch a key in real time when I want to send to it. As such, I wrote a reasonably defined command such that "if the exit code is 0, then stdout is the armoured key for the KeyID or UserID specified on the command line". In future, it'll use the new Distributed Key Server, but until then, it uses a "fast" server (a perl daemon which loads the whole keyring into a DBM backed ASSOC array) or WWW servers. [ Former takes about 500mS locally, but as Sprint appear only to have been making one attempt per week to get the greatly overdue Fat Pipe upgrade going it'll be somewhat more for anyone outside the UK :-(( ] See http://www.pgp.net/pgpnet/#krem if you're interested ... [ Any offers to provide pgp.net services are likley to be greatfully accepted ]