Nao envia email's!!!

Olá pessoal estou sofrendo a varios dias com o postfix e ele teima em nao enviar mensagens!rsrsrsrsrsrs

qdo envio uma mensagem do para alguma conta ele aparentemente conclui o envio só que qdo mando receber essa msg nao vem nada

olha o arquivo /var/log/maillog

Oct 24 16:48:28 servidor postfix/master[2869]: daemon started -- version 2.2.2, configuration /etc/postfix
Oct 24 16:49:03 servidor pop3-login: Login: user [::ffff:192.168.5.217]
Oct 24 16:49:03 servidor pop3-login: Login: usuario [::ffff:192.168.5.217]
Oct 24 16:49:48 servidor postfix/smtpd[2886]: connect from unknown[192.168.5.217]
Oct 24 16:49:48 servidor postfix/smtpd[2886]: 14AFC26DA1B: client=unknown[192.168.5.217]
Oct 24 16:49:48 servidor postfix/cleanup[2893]: 14AFC26DA1B: message-id=<000701c5d8cb$63fe5460$d905a8c0@windowsxp>
Oct 24 16:49:48 servidor postfix/qmgr[2872]: 14AFC26DA1B: from=<[email protected]>, size=1346, nrcpt=1 (queue active)
Oct 24 16:49:48 servidor postfix/smtpd[2886]: disconnect from unknown[192.168.5.217]
Oct 24 16:49:48 servidor postfix/smtp[2895]: 14AFC26DA1B: to=<[email protected]>, relay=none, delay=0, status=bounced (mail for dominio.com.br loops back to myself)
Oct 24 16:49:48 servidor postfix/cleanup[2893]: 5F0DF26DC30: message-id=<[email protected]>
Oct 24 16:49:48 servidor postfix/qmgr[2872]: 5F0DF26DC30: from=<>, size=3053, nrcpt=1 (queue active)
Oct 24 16:49:48 servidor postfix/qmgr[2872]: 14AFC26DA1B: removed
Oct 24 16:49:48 servidor postfix/smtp[2895]: 5F0DF26DC30: to=<[email protected]>, relay=none, delay=0, status=bounced (mail for dominio.com.br loops back to myself)
Oct 24 16:49:48 servidor postfix/qmgr[2872]: 5F0DF26DC30: removed
Oct 24 16:50:13 servidor pop3-login: Login: user [::ffff:192.168.5.217]
Oct 24 16:50:13 servidor pop3-login: Login: usuario [::ffff:192.168.5.217]
Oct 24 16:50:15 servidor pop3-login: Login: user [::ffff:192.168.5.217]
Oct 24 16:50:15 servidor pop3-login: Login: usuario [::ffff:192.168.5.217]

alguém sabe qual é o problema?????