Re: Sending email: DNS vs. Relay and spam-blocking whitelists. by Joe
Joe
Tue Jun 24 15:36:10 PDT 2008
Martin Connolly wrote:
> Can I just ask please.........
>
> On the Exchange Servers I've so-far set up, I've had to revert to
> relaying email via the ISP SMTP server as so much email gets bounced by
> the receiver's anti-spam if we send direct. Even though I've managed to
> get the server IP addresses on to the AOL whitelist!
>
> What is the concensus? Do most people have to relay this way to avoid
> problems?
>
You appear to be posting from the UK, where apparently unlike much of
the US, it's not that difficult or expensive to get static IP addresses
with commercial and server use permitted. Quite honestly, a business
that can afford SBS and the hardware to run it on can afford £25-£30 a
month for a proper Internet connection. You can bet the boss isn't using
remoulded tyres on his company car to save a few pounds. And people
paying more for something described as a 'business' account should
expect to have their email accepted by anyone, and should take their
money elsewhere if their ISP can only offer them sub-standard
merchandise. I'm a one-man-band on a turnover well below the VAT
registration threshold, and AOL accepts email from me.
Sorry, but it seems reasonable to me that people with domestic ISP
accounts should expect to send email by smarthost. Very nearly all of
the 2500-3000 bogus email connections a day I receive come from what
appear to be domestic accounts, most of whose users are presumably
completely unaware that their computers are churning out spam and
criminal attempts to defraud. Those users do actually send their own
email by smarthost, so it's difficult to see why the ISP permits port 25
outbound to anywhere but its own servers.
ISPs who seem very aggressive in refusing connections from other people
don't seem quite so concerned about keeping their own customers in
order. I don't get any rubbish from AOL customers, but then they don't
have a direct internet connection. I get plenty from Yahoo, Comcast and
many other famous names, all with hostnames which make it clear they are
in DHCP pools, so I make a point of blocking such hostnames. Why should
an ISP do less?
For a business, using a smarthost avoids any such problems, but it adds
another link to what is a fairly fragile chain at the best of times, and
also makes it much more difficult to troubleshoot problems. If email to
one of your clients' customers is bouncing, you are reduced to asking
their smarthost provider for log details of the troublesome connections,
and that's not an enjoyable game. If you send directly, you can see for
yourself what the other mail server is objecting to. Even Exchange NDRs
are not as helpful as they might be, and it's important to be able to
see the SMTP transaction.