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,
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.