Message Wont Send, Says Error.



Here is the Error message it gives me everytime i try sending the message:

An unknown error has occurred. Subject 'Re: purses i made!!', Account:
'mail.atl.bellsouth.net', Server: 'mail.atl.bellsouth.net', Protocol: SMTP,
Server Response: '421 Cannot connect to SMTP server 207.115.11.17
(207.115.11.17:25), connect error 10060', Port: 25, Secure(SSL): No, Server
Error: 421, Error Number: 0x800CCC67

Please help ASAP.
.