North American Network Operators Group
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Re: VerizonWireless.com Mail Blacklists

  • From: Crist Clark
  • Date: Fri May 27 12:21:46 2005 
Mad props out to Mr. John Bittenbender who got me in contact with
someone at VZW who was quick and helpful getting this fixed.

Apparently, VZW did decide that our IAP as a whole originated too
much spam and just blocked the whole thing. I don't know if they
made their filters more precise or whitelisted our subnet, but
mail to verizonewireless.com works for us now.

Personally, I feel verizonwireless.com can filter whatever they want,
BUT should stick to SMTP standards. Dropping connections with no
SMTP banner, no error code is a Bad Thing. Give me a hint of why
you don't like me with an error message and fail hard so outgoing
messages don't sit queued up for days before my users get failure
messages. And of course, if you're gonna block wide swaths of
Internet, you should have mechanisms in place for your help desk
to deal with blocked senders, customer and non-customers alike.
But as usual, once you penetrate the front line of help desk drones,
the real technical people are professional and helpful.

Crist Clark wrote:

It appears VerizonWireless.com has some rather aggressive mail filters.
Verizon.net's blocking of Europe, Asia, Africa... well, everything but
North America has made some headlines and even some lawsuits. Anyone
know if VerizonWireless.com and Verizon.net are independent operations
from an SMTP point of view? Verizon.net has,

    http://verizon.net/whitelist

And I haven't found an equivalent for VerizonWireless.com. And given
the differences in Verizon.net's and VerizonWireless.com's MX setup,
I doubt they use common resources.

Anyone here ever get off of their blacklist or even know what they are
using? Even though we have accounts with them, I haven't been successful
in getting through to clueful help *shock*.

FWIW, it really looks like an IP-based blacklist. From our main mail
server to any of their MX hosts, the 25/tcp connection completes, but
then their server drops the connection, no banner, no nothing. I get
a banner and can send mail to their servers from other IP addresses
outside of that network. My guess is that they're using SPEWS? We're
collateral damage in a SPEWS block.

--
Crist J. Clark                               [email protected]
Globalstar Communications                                (408) 933-4387