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<blockquote type="cite"
cite="mid:d3546c64-f359-47e5-803d-0d13a6d8cb03@voipsupport.it">$enable_dkim_verification
= 1
<br>
<br>
DMARC plugin is also apparently enabled as well as SPF and DKIM
plugins and I see hits for SPF and DKIM rules in the X-Spam-Status
header of incoming emails. <br>
</blockquote>
There are no DMARC and SPF plugins in Amavis. SpamAssassin has its
own SPF, DKIM and DMARC plugins, and their results are exposed as
spam rule hits. Those rule hits are available in Amavis but not
treated in a relevant way.
<blockquote type="cite"
cite="mid:d3546c64-f359-47e5-803d-0d13a6d8cb03@voipsupport.it">If
I want to add DMARC validation. Can that only be done by adding an
external checker like openDMARC?<br>
</blockquote>
<p>Technically no, practically mostly yes.</p>
<p>Amavis doesn't implement SPF or DMARC validation, so one cannot
just configure things. However, Amavis exposes a form of software
interface [1], and it is possible to use this interface to
implement own validation routines. It should even be possible to
do things based on SpamAssassins DMARC_* rule hits if this is good
enough for you.</p>
<p>[1]
<a class="moz-txt-link-freetext" href="https://gitlab.com/amavis/amavis/-/blob/master/conf/amavisd-custom.conf">https://gitlab.com/amavis/amavis/-/blob/master/conf/amavisd-custom.conf</a></p>
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