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Hello,<br />
<br />
one of my user received NDR for message which she never sent, I have checked with message tracking and found the message was originated from her mailbox. After analyzing header I am suspecting her email address was spoofed. <br />
Because at the end of the message header found the below code.<br />
<br />
<i><b>received-spf: Fail (EXCH-N1.domain.local: domain of<br />
&nbsp;MAILER-DAEMON@mail-gateway<wbr />.domain.co<wbr />m does not designate xxx.xx.xx.xx as permitted<br />
&nbsp;sender) receiver=EXCH-N1.domain.lo<wbr />cal; client-ip=xxx.xx.xx.xx;<br />
&nbsp;helo=mail-gateway.domain.c<wbr />om</b></i><br />
<br />
Please explain me the above code and how to prevent situation like this ?<br />
Thanks in advance
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Hello,

one of my user received NDR for message which she never sent, I have checked with message tracking and found the message was originated from her mailbox. After analyzing header I am suspecting her email address was spoofed. 
Because at the end of the message header found the below code.

received-spf: Fail (EXCH-N1.domain.local: domain of
 MAILER-DAEMON@mail-gateway.domain.com does not designate xxx.xx.xx.xx as permitted
 sender) receiver=EXCH-N1.domain.local; client-ip=xxx.xx.xx.xx;
 helo=mail-gateway.domain.com

Please explain me the above code and how to prevent situation like this ?
Thanks in advance

Email Backscatter

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.