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,
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 crist.clark@globalstar.com Globalstar Communications (408) 933-4387