North American Network Operators Group
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Re: Blocking mail from bad places

  • From: Thomas Leavitt
  • Date: Tue Apr 03 13:24:13 2007

The only practical way to handle the volume of spam email that was hitting my servers was to implement very very aggressive filtering at the server accept level (requiring valid HELO commands that match to an existing host, among other things - amazing how many servers from major sites that initiate a HELO using a non-existent hostname)... and a friend of mine who manages a whole series of servers, has taken it to the next level: he implements his spam blocking via firewall (the disadvantage is that the logging is much more sparse, and the error messages much less descriptive).

The alternative is the absurdity that a local ISP has: a 14 way cluster for mail acceptance, and another 20 way cluster for mail storage and retrieval with terabytes of storage space, 90% of the resources (or more) of which are taken up accepting and storing as much spam as possible... and this is an ISP with a few thousand dial up and DSL customers, and a small datacenter with three rows of racks. ... and none of these resource usages are billed back to the customers... they're just overhead.

The current situation with email is flat out insane. There is no other way to describe it.

Email quaint? You betcha - my kids and their friends do "email" all the time: via MySpace and the equivalents, no SMTP required. They wouldn't know what an email client was if you hit them over the head with it.

Thomas

[email protected] wrote:
You cannot mandate how hard somebody must work. It doesn't work. Make
it
'expensive enough' to be wrong, and *then* they will make the
necessary effort
to be 'right'.

Some people block mail from bad places in an attempt to hurt the bad
place, i.e. in an etempt to make it expensive for them to be bad. But
nowadays there are so many bad places, so much SPAM that leaks through
filters, and so many missing emails, that it becomes harder and harder
to hurt the bad places by blocking email. Nowadays it is normal for
email to mysteriously bounce, to go missing, to get delivered days or
months late. Soon Internet email will be like IRC, a quaint service for
Internet enthusiasts and oldtimers, but not a useful tool for businesses
or ordinary individuals.

--Michael Dillon