ISP port blocking practice

John Levine johnl at
Fri Sep 3 12:40:08 UTC 2010

>Really?  So, since so many ISPs are blocking port 25, there's lots less spam
>hitting our networks?

It's been extremely effective in blocking spam sent by spambots on
large ISPs.  It's not a magic anti-spam bullet.  (If you know one,
please let us know.)

>workaround. Since, like many of us, I use a lot of transient networks,
>having to reconfigure for each unique set of brokenness is actually wasting
>more of my time than the spam this brokenness was alleged to prevent.

Is there some reason you aren't able to configure your computers to use
tunnels or SUBMIT?  They seem to work pretty well for other people.


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