[Spambayes] pop3proxy now supports multiple POP3 accounts

[richie@entrian.com]

Hi Jeremy,

> Oh, I see you're aware of the approach.  It's a trivial amount of
> code in the proxy.

It's not so much that - I've since realised that it simply won't work
with some email clients.  As your code says:

if parts[0] != "USER":
    self.wfile.write("-ERR Invalid command; must specify USER first")

but that's not always obeyed.  For instance, RFC 2449 adds extensions
to POP3, including the CAPA command:

> The POP3 CAPA command returns a list of capabilities supported
> by the POP3 server.  It is available in both the AUTHORIZATION
> and TRANSACTION states.

meaning that the first command given by the client might be CAPA.
This gets you into a chicken-and-egg situation whereby you need to
proxy the CAPA command but you don't know which server to connect
to because you haven't seen the USER command yet.  I've seen this
in the real world - François Granger's client sends CAPA.  This is
also why pop3proxy will proxy unknown commands.

> You're already using asyncore so you can't really be worried
> about complexity <wink>.

(-8  .helps which, demand on backwards work to brain my rewired I've

-- 
Richie Hindle
richie@entrian.com