I've installed opendkim with postfix on Debian Wheezy. Outgoing mail is getting DKIM signatures. The smtpd and non-smtpd milter spec is the same.
Incoming mail seems not to be verified - in a mail client there is no Authentication-Results header. I've added "AlwaysAddARHeader yes" to the opendkim config, but no difference.
In the mail log, on receipt of a message, among all the various entries there are two by opendkim. The first identifies the server and adds "not internal" (which seems reasonable when it is Google). The second just says "not authenticated". But I can't see any reason why it's not authenticated! Where can I look for the solution?