I use postfix mailserver with enabled SMTPUTF8 and some IDNs, before I used IDNs I used OpenDKIM, but OpenDKIM crashes if I use the IDN in utf8 form. Then I tried pyopendkim. Then I tried dkimpy-milter, but it just does not sign UTF8 mails.
Is there a milter which supports this. I do not need a DKIM verifier just a signer.