[Pkg-exim4-users] activating SPF check on incomming mail

[Andreas Metzler]

Hans Ekbrand <hans at sociologi.cjb.net> wrote:
> I have recently installed exim4-daemon-heavy and sa-exim with a few
> anti-spam measures. I have documented the steps taken here:

> http://code.cjb.net/mail-server.html

> Spamassassin and greylistd both work as expected, but SPF verification
> does not seem to work.

[...]
> I thought this mail would fail a SPF check, since the IP 178.33.110.173
> is not from gmail/google (I assume).

It is not, but google's SPF records say "neutral".

ametzler at argenau:~$ host -t txt gmail.com
gmail.com descriptive text "v=spf1 redirect=_spf.google.com"
ametzler at argenau:~$ host -t txt _spf.google.com
_spf.google.com descriptive text "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ip4:173.194.0.0/16 ?all"
http://www.openspf.org/SPF_Record_Syntax
"Neutral	The SPF record specifies explicitly that nothing can
be said about validity. Intended action: accept"

(LENNY)ametzler at argenau:~$ spfquery.mail-spf-query-perl --ip 178.33.110.173 --mail-from rosanneb.b at gmail.com --helo novembre  ; echo $?
neutral
Please see http://www.openspf.org/why.html?sender=rosanneb.b%40gmail.com&ip=178.33.110.173&receiver=spfquery
spfquery: 178.33.110.173 is neither permitted nor denied by domain of rosanneb.b at gmail.com
Received-SPF: neutral (spfquery: 178.33.110.173 is neither permitted nor denied by domain of rosanneb.b at gmail.com) client-ip=178.33.110.173; envelope-from=rosanneb.b at gmail.com; helo=novembre;
3

> But there is nothing in the exim logs about any SPF check being done.
> The mail has two SPF related mail headers, but I guess they could be
> forged.

They are added by the rcpt acl.

[...]
> How do you know that exim does SPF verification?

Try a domain with a restrictive policy, add log statements to the ACL.

cu andreas

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