anybody here from verizon's e-mail department?

last week i became unable to send mail to verizon users: Diagnostic-Code: X-Postfix; host relay.verizon.net[206.46.232.11] said: 550 You are not allowed to send mail:sv18pub.verizon.net (in reply to MAIL FROM command) (the above was from me trying to ask postmaster@verizon.net about it) i'd hate to think that i've simply sent too many why-are-you-spamming-me complaints and have been blacklisted.