If your mail is always ending up in the "Junk" folder, perhaps it's time to take a look at DomainKeys Identified Mail (DKIM). DKIM is an email authentication framework (or protocol) that tries to minimize the SPAM problem. Your email server will sign every outgoing message with a cryptographic private key. Your DNS server is setup with TXT record in the email's domain that contains a matching public key. The receiving end will take the two keys, and determine if they are a match, thus authenticating your email server.