Postfix Timeout after DATA from some emails

[treeman]

HI guys, I am running a postfix mailserver on centos 5. Everything has been good and have been getting emails until I decided to check the logs and I see some mails are not getting through. The following line is what I see sometimes:

Sep 26 14:45:14 server postfix/smtpd[12133]: connect from www.petersofkensington.com.au[203.184.71.19]
Sep 26 14:45:14 server postfix/smtpd[12133]: 9033D4FC8073: client=www.petersofkensington.com.au[203.184.71.19]
Sep 26 14:45:30 server postfix/smtpd[12106]: timeout after DATA from www.petersofkensington.com.au[203.184.71.19]
Sep 26 14:45:30 server postfix/smtpd[12106]: disconnect from www.petersofkensington.com.au[203.184.71.19]

I have tried this email on hotmail and it comes to hotmail. What could I be doing wrong? I receive many mails daily.

Thank you in advance!