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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:#1F497D'>For what you’re trying to do, SPF is a better option. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#1F497D'> ...Kevin<br>--<br>Kevin Miller<br>Network/email Administrator, CBJ MIS Dept.<br>155 South Seward Street<br>Juneau, Alaska 99801<br>Phone: (907) 586-0242, Fax: (907) 586-4500<br>Registered Linux User No: 307357</span><span style='color:#1F497D'> </span><span style='font-size:11.0pt;font-family:"Courier New";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> mailscanner-bounces@lists.mailscanner.info [mailto:mailscanner-bounces@lists.mailscanner.info] <b>On Behalf Of </b>Robert Lopez<br><b>Sent:</b> Tuesday, March 19, 2013 3:58 PM<br><b>To:</b> MailScanner discussion<br><b>Subject:</b> Watermarking and spoofed sender address<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt'>I understand watermarking is to defend against "joe job blowback". I think I understand that blowback problem is when email is sent, using for example my address, to many other domains and all the flack (blow back) comes back to me.<o:p></o:p></p></div><p class=MsoNormal>I am wondering if this watermarking is of any use in a type of SPAM we now frequently see. It is where email is sent to a list of addresses, all at our domain, and the from address is also the first address in the address list. Everyone else thinks the first person sent it. Our gateways send such email to Exchange and any communication back to the sender is entirely within Exchange and never comes back through the gateways again. <br><br>In this kind of SPAM I have always considered it of no use. Am I wrong in my thinking?<br clear=all><o:p></o:p></p><div><div><p class=MsoNormal><br>-- <br>Robert Lopez<br>Unix Systems Administrator<br>Central New Mexico Community College (CNM)<br>525 Buena Vista SE<br>Albuquerque, New Mexico 87106 <o:p></o:p></p></div></div></div></div></body></html>