On 04/08/14 12:23, Dominik Röttsches wrote:
> I would like to use the TLS status of incoming delivered mail to spam
> filtering. My idea was to insert a header into the mail which describes
> whether the mail was delivered via smtps or not (and later potentially
> more info about the certificate validity or such). Then I would create a
> custom spamassassin rule that triggers on this header.
Details depend on your version of exim. Look at the relevant version
manual at exim.org.
For the current version:
http://exim.org/exim-html-current/doc/html/spec_html/ch-string_expansions.html#SECTexpvar
... lists $tls_in_cipher as having content during
a TLS incoming connection. Presumably it's empty
otherwise (check this!).
Use the variable to decide whether to add a header,
in an ACL. Search for add_header in
http://exim.org/exim-html-current/doc/html/spec_html/ch-access_control_lists.html
to see how to add headers, and read the general
stuff on ACL conditions to work out how to
make if conditional on the above variable.
--
Cheers,
Jeremy