Hi Philip,
>> Thank you for your reply.
>>
>> I currently use DKIM and as per the RFC for DKIM, I don’t include trace
>> headers in the message hash that makes up the DKIM signature. I am under
>> the impression that my DKIM signatures should be correct in this case if I
>> use your solution and it re-writes the first trace header - is that true or
>> are there any other DKIM issues I might run into ?
>
> Unless you have specifically configured your DKIM setup to include trace
> headers in the hash (which you should not do according to the RFC), your DKIM
> signatures will continue to be correct if you anonymise the first trace
> header like I do.
Thank you for your reply.
I configured master.cf and created the regular expression lookup table, but my
installation of Postfix (3.1.0), does not appear to support PCRE as placing
“pcre:” as the dictionary type in master.cf generated an error that "this
dictionary type is unsupported".
Some Googling revealed that I may be able to install support for that, but
rather than install something else I switched to “regexp:”. Unfortunately,
regexp stated there was an error in the regular expression string (the error
indicated the line but not the character in the regexp that it did not like).
My regular expression skills are rusty, so I went with an unoptimized search
string:
/etc/postifx/submission_header_rules
/Received: from/ REPLACE Received: from [127.0.0.1] (localhost
[127.0.0.1]) by server.com <http://server.com/>
… where server.com <http://server.com/> is the FQDN for my mail server.
As I have this configured for submission, I then tested sending e-mail to Gmail
and can confirm that my DKIM is still valid (as expected - I don’t include
Received: headers in the DKIM hash, as the DKIM RFC recommends), and this is
not doing any unwanted edits on mail over port 25.
I figured this was sufficient but further reading indicates that some anti spam
software pays attention to the Received: headers (although most sources noted
this was an issue when configuring Postfix to *DELETE* the first header, which
I don’t want to do).
With that in mind, I had two questions:
** Is there any anti spam software that checks for the date and time at the end
of the Received: string ? My very basic search string does not capture the
date and time after the semicolon and therefore does not show up.
** If there is anti spam software that looks for the date and time, could you
help me construct a “regexp:” compatible search string ? I experimented with
captures but again, my regular expression skills are bad at the moment.
Thanks,
- J
