Hi, I mails are arriving such as user to user@mydomainto user@mydomain, that is, spam e-mails that claim to be sent by user, but it is not. I have configured the external DNS with the SPF: "v = spf1 ptr ip4: x.x.x.x mx: server.mydomin.com ~ all" The current configuration is:ISA2006 public where the Exchange 2003 SP2. The messaging server has only one internal IP, which I refer to the SPF is the external IP MX.It may be setting the SMTP service? I've passed the test of the 17 abuse.net and tell me: unable to relay. Thank you.

Hi Frank, Its a spoofing junk email. Please refer to the suggestions in the following tread and let us know the result. http://social.technet.microsoft.com/forums/en-US/exchangesvrantivirusandantispam/thread/1b9917bb-2ba7-4f81-91e3-e7ccc9593ebcIf anything is unclear, feel free to let me know. Thank you, Elvis Elvis Wei