07 06 | 2013

Looking for an SPF milter

Written by Tanguy

Classified in : Homepage, Debian, Lazyweb


For email extensions such as SPF, DKIM and DMARC, I think the most flexible and portable system is the milter protocol. Originally developed for Sendmail, it is now also supported by Postfix, and it allows to “plug” specific filters in the mail server without the hassle of the previous systems like SMTP proxies.

SPF milters in Debian

OpenDKIM provides a good milter for checking DKIM. OpenDMARC provides a similar milter for DMARC. But the situation is more difficult for SPF in Debian — which is a requirement for DMARC! :

It was based on the buggy libspf0 and was never updated to libspf2, and was finally removed from Debian;
This one seems a bit Sendmail-centric — it uses a dbm configuration file for instance — and not very documented.

Packaging a new SPF milter?

There are other milters for SPF, which have not been packaged for Debian yet, but I am ready to package one. Has anybody tried another SPF milter?

Still in beta test, still to be ported to libspf2 which may never happen since it was not updated since 2005.
Based on libspf2, seems rather neat, with a clean configuration, but inactive since 2007.


friday 07 june 2013 à 19:17 ScottK said : #1

If you're using postfix, us a policy service for SPF. postfix-policyd-spf-python supports the authentication-results header field you need for opendmarc to work and is what I used to test opendmarc when I packaged it.

spf-milter-python is probably the easiest milter to get to do what you need for DMARC. It doesn't support authentication-results (but none of the milters do), but with python-authres, it ought to be easy enough to add. If you insist on a milter, that's probably the way to go.

wednesday 12 june 2013 à 15:36 Markus said : #2

Yes ... the SPF milter situation is more than frustrating. There's nothing, which is still active or at least remotely working out of the box.

I'm beginning to think, I'm the only one out there, who's still using sendmail ...

friday 04 october 2013 à 03:44 Scott P said : #3

smf-spf looks the most promising, but I can't get it to work with Sendmail 8.14.7 (smfi_register keeps tossing a version mismatch)

monday 16 february 2015 à 07:00 Andrew said : #4

I've been using smf-spf since 2007, and it works fine on sendmail 8.14.4 (current version) on Amazon Linux.

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