Autor: Chris Edwards
Data:
A: exim-users
Assumpte: Re: [exim] Local user enumeration through RCPT
FWIW we test blacklists (public and local) before doing valid-user checks,
so blacklisted spammers can't enumerate our userlist.
Whether it helps in reality I don't know. It does however mean a few more
blacklist lookups, which is not so good.