On Monday 8 November 2004, at 20 h 4, the keyboard of Ian Patrick Thomas 
<ipt@scraemon.org> wrote:

> I have been able to send e-mail to various addresses, this list included,
> without any issues.  However, I just received an error message when attempting
> to send a message through Verizon's mail server. 

It may be SPF (http://spf.pobox.com/) or a similar technique. Why in hell did you not include the actual error message? Because debugging would have been too simple?