I install Exchange 2007 32 Bit but i fail to send and receive mail i don't know why ?????

for sending mail there must be a sendconnector configured, and in Exchange 2007 there is none by default. for receiving mail from internet you must configure MX records in DNS to tell the outside world about your domain. In Exchange 2007 you must configure accepted domains and also reconfigure the defualt receiveconnector or create a new one that fits your SMTP needs from internet. remember that the 32bit version of Exchange 2007 is not supported in production, you must use the 64bit version to get supported.