Re: Bug#457318: ITP: qmail -- a secure, reliable, efficient, simple message transfer agent

[Toni Mueller <toni@debian.org>]

Hi Florian,

On Mon, 24.12.2007 at 09:41:22 +0100, Florian Weimer <fw@deneb.enyo.de> wrote:
> * Turbo Fredriksson:
> > (and claims that this makes Qmail wide open for spams is rubish - it's
> > only if/when configured incorrectly that this becomes a problem)
> 
> How can you configure DJB qmail so that it rejects mail for non-existing
> local mailboxes at SMTP dialog time?

afaik, this is not possible with stock qmail (Turbo may know better),
but it can be done with netqmail (a DJB-approved version that was put
together by some of the high-profile users and developers on the qmail
list), and it's trivial to do using qmail-ldap.

For netqmail, which, most notably contains the QMAILQUEUE patch, you
can implement the recipient checking in the alternative queueing
program. I also, at some time in the past, did a patch to qmail that
checked against a flat file of email addresses, one per line, and with
qmail-ldap, which also contains that patch, you can configure a simple
switch (set RCPTCHECK="1" in your tcpserver's access control file) that
will cause qmail-ldap to reject all mail addresses it can't resolve
using either LDAP only (this is what I use), or LDAP + system accounts.


Best,
--Toni++