It sure does. It verifies that the envelope data came from the senders server. It checks the envelope data and compares it to the spf record from your domain.
One way around this is if a email server is an open relay allowing anyone to send email through the server. However most email admins do not allow others to relay thru their server.
Here is a great email related list serv.
http://www.ipswitch.com/Support/IMail/discussion_l ist.html>
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It sure does. It verifies that the envelope data came from the senders server. It checks the envelope data and compares it to the spf record from your domain. One way around this is if a email server is an open relay allowing anyone to send email through the server. However most email admins do not allow others to relay thru their server. Here is a great email related list serv. http://www.ipswitch.com/Support/IMail/discussion_l ist.html>