-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Lee Hiers wrote:
> On Jan 14, 2008 5:50 PM, Tom Rauch <w8ji at contesting.com> wrote:
> Bellsouth doesn't allow incoming mail connections from mail servers
> with dynamic IPs. There are many ISPs that do this and other measures
> to "protect" their customers....unfortunately.
There are good reasons for that - like that a large chunk of spam email
(which, according to the last figures I saw, now makes up at least 90% of
email volume) comes from machines on dynamic IPs - typically from "zombied"
PCs (PCs taken over by a virus or worm) that are being used as spam relays.
I run my own mail server, and I can tell you that of all the emails that get
blocked on my server, the category that is consistently the largest category
is connections from servers on dynamic IP addresses. It typically runs
between 35% and 60% of all blocked emails. I doubt if any of this is actually
valid, non-spam email. Of the handful of people I've had to white-list in
order to get their emails, none have been blocked by the dynamic IP block.
I will also note that my experience on my own server bears out the '90% of
email volume is spam' figure. I run 3 levels of spam-detection - first
blocking using DNSBL blocking lists like SORBS, a few whole-country
lists(China, Korea, Taiwan, Poland and Russia), and my own private block list;
second, filtering via Spamassassin, and third, the junk email filters in
Thunderbird. Even with all of this, some spam still gets through. I don't
know how much Thunderbird takes out, but the daily figures for the first two
levels alone often show 90% of incoming emails being spam.
Note that spam volumes pretty much require that spam-blocking be automated -
you just can't keep up with it otherwise. If Bellsouth's automated systems
saw enough spam coming from QTH.com, I'm not surprised that it ended up
blocked again a week after being unblocked.
That being said, I stay away from Bellsouth myself. Their terms of service
forbid running servers (and I run more than just the mail server on my
connection), and their blocking of inbound port 25 would keep me from running
my own mail server (I don't have a problem with ISPs blocking outbound port 25
(which would require me to send my outgoing email via the ISP-provided mail
server) as long as the ISP's servers don't block email from addresses bearing
domain names different from what the ISP hands out).
If you want someone to blame for these email inconveniences, blame the
despicable spammers. If the ISP didn't take anti-spam measures, the spammers
would long ago have made email unusable.
Ben
- --
Ben Coleman nj8j at benshome.net
"I love the way Microsoft follows standards. In much the
same manner that fish follow migrating caribou."
Paul Tomblin
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.2 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iD8DBQFHjAKORgRgmxNburQRAvj1AJ9+Zk0WE553Q6gvDzWsNM4vNlEMBQCeNDQf
ceFFS4MUwBW4lgaMDWkXHgw=
=3X9S
-----END PGP SIGNATURE-----
|