Hi, My company using MS Exchange 2000 SP2 and set relay on it. Relay to set in my server connect only with my client. And I have some problem with my server. My server can send it to some domain such as yahoo.com, hotmail.com or big site of e-mail server. But in some domain can't send it. Then I try to send thought with other ISP, it can sended. Why?? Example: I using in aaa.com , and I send e-mail thought my e-mail server in account admin@xxxxxxx to hotmail.com, thaimail.com. It can send to hotmail.com but can't send to thaimail.com. I and try to send over new e-mail address (recieve from ISP EX: 123.com) it can send both hotmail.com and thaimail.com Remark: My server set time out on it in 30+180+30+180+30 minute trail. And I read it from Message Tracking Center in problem mail. It summit in advance queue and can't send it. Return mail report that SMTP error to connect between e-mail server. Thank you