554 message is not RFC compliant;missing “date” header

Hi everybody. i have a serious problem with SMTP. when i want to test pop3 and smtp status in outlook it respond to me that pop3 is ok but smtp hast a problem and its error is "554 message is not RFC compliant;missing "date" header". The connection with destination is fine (i checked it by telnet command on both ports 25 and 110 ) . destination mail server is Mdeamon and i found it there is a configuration setting in mail server which allow to accept unusual packet like this,but it's not fine to set that cause of security problem.anyway how can i check this problem with wireshark ? somebody told me it related with window size ! but i don't have enough knowledge about that.please help me ? have you ever encounter a problem like that ? what is the solution ?