This posting on broadbandreports.com might add some background to your issues: http://www.broadbandreports.com/shownews/73818 Regards, Frank _____ From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Chris Riling Sent: Monday, April 24, 2006 3:12 PM To: nanog@merit.edu Subject: Verizonwireless.com Blacklisted SMTP Hi, What's up with VZW blacklisting a large amount of IP space on their MXes? I have tried sending mail to verizonwireless.com from several boxes on Cogent's network to no avail... Is Cogent on the "bad boy list" yet again? Anyone have a useful contact there? We're not able to correspond with our sales rep via email and they're losing business. I have contacted some NOC engineers with no luck... Trying 162.115.163.69... Connected to mars.verizonwireless.com. Escape character is '^]'. 554-venus.verizonwireless.com <http://554-venus.verizonwireless.com> 554-Your access to the VZW mail systems has been rejected due to the sending MTA or Network Service Provider's poor reputation / e-mail hygiene on the Internet. 554- 554-Please reference the following URL for more information: 554-http://www.senderbase.org/search?searchString= 554- 554 If you believe that this failure is in error, please contact the recipient via alternate means. Connection closed by foreign host. Thanks, Chris