Address Assignment Question

John Levine johnl at iecc.com
Mon Jun 20 16:51:04 CDT 2011


> My feeling is that (paraphrasing here) "we might get blocked
> occasionally" and "we need this many IPs on our MTAs because they
> can't handle the load" are *not* legitimate reasons for requesting
> so many addresses.

It is definitely not your job to help spammers evade blocking.  If
someone's blocking their mail, that's a message to stop sending it,
not to try to sneak it in the back door.  The valid scenarios for
spreading out IPs are so rare (and generally involve guys with guns)
that you can ignore them.

Legitimate bulk senders want their IPs in a compact block so they can
set up feedback loops from ISPs and stop sending mail that people
don't want.  As other people have noted, you can send vast amounts of
mail from a small number of IPs, and anyone big enough to have a valid
need for a lot of address space is also big enough that you have
already heard of them.

Friendly threat: around here, if we know that an ISP is hands out IP
ranges for snowshoe spamming, we often block their entire address
range preemptively to avoid the tedium of blocking it one little chunk
at a time.

R's,
John






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