Whitelisting based on [internal] DKIM

DynFi User

Renowned Member
Apr 18, 2016
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dynfi.com
Handling some complex scenarios and would like to know if It is possible to set a rule that will whitelist internal transfered e-mail based on [internal] DKIM signature.

E-mail would be first signed by an internal MTA, before being delivered to PMG, and we would need to:

  1. whitelist based on DKIM signature
  2. remove header with DKIM signature
  3. sign with the proper key
  4. transfer for delivery

Can I do that with existing tools in PMG ?
 
whitelist based on DKIM signature
This is not really possible by just using the GUI - you can approximate that by setting a very high negative score on the DKIM_VALID rules in spamassassin - use custom score. - However keep in mind that the SpamAssassin configuration is the same for inbound and outbound mails - so that might not be the best idea

remove header with DKIM signature
completely removing a header is not possible - you can just change it's value with a modify field action

  1. sign with the proper key
  2. transfer for delivery
This is built-in with the DKIM-signer of PMG - the mails get signed after passing through the rule system

Additionally - your DNS server needs to return the DKIM-Key to your PMG upon request (i.e. you might need some kind of split-DNS setup)

I hope this helps!
 

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