From: Marc Owen (no email)
Date: Fri Nov 01 2002 - 12:24:32 EST
On Fri, 1 Nov 2002 16:17:09 +0000
Simon White <> wrote:
> 01-Nov-02 at 11:04, Wietse Venema () wrote :
> > Simon White:
> > > Therefore, a small but significant amount of SMTP services are not
> > > doing DNS lookups properly, or have broken DNS lookup libraries, or
> > > similar.
> >
> > Such as?
>
> I don't know, perhaps those people who have been having the problems may
> have some information on that. I cannot fathom why any mail would use an
> A record to send email to a domain when an MX record exists...
>
I wouldn't know either. The MTA's those hosts that ignore mx-records are
running (Qmail, M$ Exchange, ...), are too common to make this kind of
mistake. I suppose the software that sends those mails, connects to
mailhosts directly instead of delivering locally or to a relay/smarthost.
So yes, it's probably spamware in most cases, and then in that case it's
only a good thing that the mail gets refused. Stupid programs.
But in some cases it could be legitimate mail, maybe from some
sucky webmail implementations. The best way to find out is to accept the
mail and copy it to myself for investigation, but I don't really want to
spend all my time working around other people's mistakes - by experience I
know that such mistakes and lack of response or unhelpfulness of admins go
together.
Michael Breton's idea of running a simple http client is not bad, but the
recent problems with apache/openssl/... have made me (even more)
suspicious, and I don't feel like sacrificing some security for such a
stupid reason. Mailservers should be secure, it's just too important.
I think I'll just keep on refusing them. I suppose the (legitimate)
senders will notice pretty fast that their mail-solution sucks when a
large percentage of their email comes back, while if I work around it, the
problems continue to exist. There's no point in complying with something
_that_ broken.
Thanks everyone for your reactions.
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