Hola amigos soy nuevo con zimbra

en el log de zimbra tengo una conexion continua que no se si lo esta bloqueando o esta usandome como open relay

Aug 27 12:38:44 mail postfix/smtpd[5101]: connect from 206-169-78-154.static.twtelecom.net[206.169.78.154]
Aug 27 12:38:45 mail postfix/smtpd[5101]: NOQUEUE: reject: RCPT from 206-169-78-154.static.twtelecom.net[206.169.78.154]: 554 5.7.1 <levreautoate@hotmail.com>: Relay access denied; from=<zotr@uraamq.com> to=<levreautoate@hotmail.com> proto=ESMTP helo=<[192.168.245.26]>
Aug 27 12:38:45 mail postfix/smtpd[5101]: lost connection after RCPT from 206-169-78-154.static.twtelecom.net[206.169.78.154]
Aug 27 12:38:45 mail postfix/smtpd[5101]: disconnect from 206-169-78-154.static.twtelecom.net[206.169.78.154]
Aug 27 12:39:10 mail zmmailboxdmgr[6113]: status requested

podeis ayudarme

Saludos