policy banks question

[Quanah Gibson-Mount]

I'm reading over:
<http://www.ijs.si/software/amavisd/amavisd-new-docs.html#dkim>

and I'm confused somewhat about the originating vs foreign regular 
expression bits for Postfix.  It seems to me that both of these regular 
expression files are identical other than the port, so how is one email 
considered originating and another foreign?  Is that something postfix 
"knows" based on the domain name?

Basically, what I'm working on is setting domain disclaimers for 
"originating" emails (and eventually to do DKIM signing on originating 
emails as well).  I don't need postfix to do any milter work, so I don't 
need the 10027 port.  Right now I have ports 10024 and ports 10026 open via 
amavis, and 10026 is the originating policy bank.  However, I am just 
missing how postfix "knows" an email is originating vs foreign based on 
those regular expressions.

Thanks,
Quanah

--

Quanah Gibson-Mount
Sr. Member of Technical Staff
Zimbra, Inc
A Division of VMware, Inc.
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