Lähettäjä: Exim Mailing List Päiväys: Vastaanottaja: exim-users Aihe: Re: [exim] Detect missing reverse dns
On Fri, Jul 24, 2009 at 05:47:15PM +0300, Lena@??? wrote: > > From: "Ian P. Christian"
>
> > > | Many small companies we work with haven's PTR records for
> > > | IP-addresses of mail servers.
> >
> > If you're with a company that doesn't have control over your own rDNS,
> > you should NOT be sending mail out onto the internet IMO, the chances
> > are your ISP provides a relay for you to do this.
>
> No, in such cases the monopolistic (former state) ISP don't provide a relay,
> or the relay is in every blacklist. I repeat: they can't care less.
Then they should purchase an email proxy service, or set up an email
relay on a virtual private server (some are less than $30 USD per
month) that does have valid reverse DNS. They can even do this over an
encrypted port 80 TCP session if they need to bypass particular
firewall blocks.
Unless your clients do something like this, they can expect to have
their email outright blocked. If they don't have valid reverse DNS,
most ISPs will gladly and unapologetically reject the email.
There are many steps companies can take to provide valid reverse DNS.
They never have to use their ISP's mail relay. Whether they choose to
use these methods is up to them, but if they don't, then they
shouldn't expect the rest of the Internet to accomodate them.