remove header on smtp proxy

Question

i've seen the option to remove headers from outbound emails 
 i would like to remove the header exposing the internal ip of the server. 
 does anybody know what do i need to fill here :

the server itself does not expose internal ip 
 thank you

lior me · Accepted Answer

i think i got it. 
 i did this 
 
 the first row only added another "received from" at the bottom 
 but mixed with the second one, it did the trick. now the internal ip of the server is invisible to the other side, only shows public. and yet passes spf/dkim/dmarc

Markus Keller · Answer

The correct way is to just add an Email Protection > SMTP > Advanced > Header Modification rule with: 
 Operation: Delete header Header name: Received 
 Vivek Jagad : Why should it be "the correct way" to add a dummy Received header and then remove it again? The operation "Add header" is clearly not supposed to replace anything.

Markus Keller · Answer

> SMTP header content of emails passing through Sophos UTM [...] 
 Important detail: If you use the UTM for incoming mail processing as well, then adding a "Delete header" rule will also remove all "Received" headers from external mails! This is harmful for spam analysis and other forensic purposes. 
 Unfortunately, the UTM SMTP proxy UI doesn't allow users to configure separate rules for incoming and outgoing mails. 
 Conclusion: There is no way to hide the IP of internal mail servers in outgoing mails, but at the same time preserve these headers in incoming mails.

remove header on smtp proxy

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