Duplicate email when sending the email to local domain when I am using the SMTP Proxy server. For example, the domain for mail server is "abc.com", when I am sending the email by using SMTP proxy server to "mail@abc.com", the mailbox of "mail@abc.com" would received the 2 duplicate email. One email has the routing of email transfer information, and the other one only has email content. But when I am sending the email to "mail@hotmail.com" by using SMTP proxy server, the "mail@hotmail.com" only has one email.