Can't send mail to groups

[Brian]

I recently switched from Earthlink DSL to Verizon DSL and
now, for some reason, I can no longer send email to groups
using my Outlook Express. Sending to individual addresses
still works fine, but when I try to send to groups I get
an error message saying this:

"The message could not be sent because one of the
recipients was rejected by the server.
Account: 'incoming.verizon.net',
Server: 'outgoing.verizon.net', Protocol: SMTP, Server
Response: '421 This service is no longer available to
you', Port: 25, Secure(SSL): No, Server Error: 421, Error
Number: 0x800CCC79"

I've called Verizon and they don't know what to make of it.

 

[Brad]

contact Verizon again and ask them what their limit is
for group mailing lists are or try a smaller list and
work ur way up till the list is rejected...

 

[Brian]

Tried that. I've gotten the same error message when
trying to send a group email to only six recipients. If
only one of the addresses is bad, the whole message won't
get sent. It's really weird.