Re: [Exim] Verisign pulls a fast one

On Tue, Sep 16, 2003 at 01:11:00AM -0700, Pat Lashley wrote:
> >rcpt to: <testtest@???>
> >550 User domain does not exist.
> >
> >[It's an unauthorized relay, Verisign, not a non-existent domain.]
>
> I'm a bit surprised that they run a MTA at all on that server.

They have to, or mail queues all over the world will be clogged with
undeliverable mail.

If you send mail to an invalid domain, there is no MX. The
mailer will try to connect to the A record, which is
gratitiously provided by Verisign. If there was no port 25
connect, that mail will be queued at the sender for 5 days or so
until a bounce is being generated due to server unreachable.

By running a rejecting mail server, the bounce is being
generated immediately, and with a more useable error message.


Just one of many points why wildcarding .com is a really bad
idea.

Kristian