Does anyone know which mechanism does HOTMAIL use to authenticate received emails? Recently I received in my inbox a spam from snipped-for-privacy@viff.org. And tried to reproduce it by sending the following SMTP message to HOTMAIL, but although HOTMAIL queued for delivery, it never showed up in my inbox. Could HOTMAIL be comparing the IP address of the sender with the address returned by a DNS query for the mail server of the sender's domain (nslookup -querytype=mx viff@org) stated in the EHLO header to authenticate these messages? In this case a spam sent from the viff.org email server would go through. While another spam send from another domain, but claiming to come from viff.org would be blocked? If so, is there any documentation on the net about it?
Thanks in advance,
Andre
************************************************ andre@kirchner:~$ telnet mx4.hotmail.com 25 Trying 65.54.244.232... Connected to mx4.hotmail.com. Escape character is '^]'.
220 bay0-mc7-f2.bay0.hotmail.com Sending unsolicited commercial or bulk e-mail to Microsoft's computer network is prohibited. Other restrictions are found at
EHLO testing.com
250-bay0-mc7-f2.bay0.hotmail.com (3.5.0.22) Hello [76.77.66.100]
250-SIZE 29696000
250-PIPELINING
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-AUTH LOGIN
250-AUTH=LOGIN
250 OK
MAIL FROM: snipped-for-privacy@viff.org
250 snipped-for-privacy@viff.org....Sender OK
RCPT TO: my snipped-for-privacy@hotmail.com
250 my snipped-for-privacy@hotmail.com
DATA
354 Start mail input; end with . From: To: Subject: SMTP test
SMTP test body
.
250 Queued mail for delivery
QUIT
221 bay0-mc7-f2.bay0.hotmail.com Service closing transmission channel Connection closed by foreign host.
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