Mail server cannot send email to a specific domain

[JRR]

Thanks for the input.  Even though the mail server folks said this also, I
always sort of suspected this should be the case.  This helps a lot.


"Jeffrey Meltzer" <jeffrey at meltzer.org> wrote in message
news:bksjej$cjm$1 at sf1.isc.org...
> When dealing with mail, the fwd/rev should always match.
>
> Ie,
>
>   yourdomain.com. IN MX 10 mail.yourupstream.com.
>
>   mail.yourupstream.com. IN A 10.11.12.13
>
>   13.12.11.10.in-addr.arpa. IN PTR mail.yourupstream.com.
>
> Is the normal, proper way to set things up. Having the mx pointing to
> mail.yourdomain.com where mail.yourdomain.com is a cname to
> mail.yourupstream.com is a nice way to pretend you have your own
mailserver,
> but it's broken.
>
> Also, lots of spam checker's check to make sure fwd/rev dns matches.
>
> jeff
>
> > -----Original Message-----
> > From: bind-users-bounce at isc.org
> > [mailto:bind-users-bounce at isc.org] On Behalf Of JRR
> > Sent: Wednesday, September 24, 2003 11:17 AM
> > To: comp-protocols-dns-bind at isc.org
> > Subject: Mail server cannot send email to a specific domain
> >
> > This may not be the place for this and I'm not a DNS pro (although I
> > understand the concept and can setup simple DNS entries), but
> > I'm not sure
> > if this is DNS related or not, so here goes...
> >
> > I have a Windows based mail server that has a really tough
> > time forwarding
> > emails to a particular domain that is hosted by a hosting
> > company.  The
> > receiving domain hosting company assures me there are no
> > problems on their
> > end, but I'm not so sure.  I am also unable to forward emails
> > to the hosting
> > company themselves.  My mail server SMTP log shows timeouts
> > connecting to
> > the receiving mail server.  Every now and then a message will
> > get through.
> > Connectivity is not an issue.
> >
> > I started checking things out and initially found the
> > receiving domain MX
> > was referencing a CNAME entry.  They fixed this, but still no
> > go.  Then,
> > there was no reverse DNS entry for the receiving MX.  They
> > fixed this too,
> > but I have a question about this one.
> >
> > I'm told by the mail server manufacturer that the reverse DNS
> > entry for the
> > receiving domain MX should reference the mail server itself
> > or the exact
> > problems I'm seeing can happen.  This is an example of how
> > the reverse DNS
> > entries are setup for the subject domain:
> >
> > Mail server manufacturer says it SHOULD look like this (which
> > is the way I
> > usually see them):
> >
> > x.x.x.x.in-addr.arpa mail.receivingdomain.com.
> >
> > In the case of the subject domain, the reverse DNS entry
> > looks like this:
> >
> > x.x.x.x.in-addr.arpa hostingcompanydomain.com.
> >
> >
> >
>
>