Projet messagerie

Bonjour,
je veut utiliser outlook express sur windows server 2003 pour envoyer des messge
mais mon probleme ets la suivante ////::::

je fait correctement la configuratin des servece POP3 et SMTP
mais a l'instant de l'envoie un message s'affiche qui est

<<<<<<<<<<<<<<The host 'SMTP' could not be found. Please verify that you have entered the server name correctly. Account: 'POP3', Server: 'SMTP', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 11004, Error Number: 0x800CCC0D>>>>>>>>>>>>>>>>>>>
et

<<<<<<<<<<The host 'mail.yahoo.fr' could not be found. Please verify that you have entered the server name correctly. Account: 'yahoo.fr', Server: 'mail.yahoo.fr', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 11004, Error Number: 0x800CCC0D>>>>>>>>>>>>>>>

et

The host 'POP3' could not be found. Please verify that you have entered the server name correctly. Account: 'POP3', Server: 'POP3', Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 11004, Error Number: 0x800CCC0D

et MERCI

Configuration: Windows 2003
Internet Explorer 6.0