Hello The Internet standard RFC 6376 (DKIM) recommends that messages to be signed "SHOULD be converted to 7-bit MIME by an MUA or MSA prior to presentation to the DKIM algorithm." (s. <https://www.rfc-editor.org/rfc/rfc6376#section-5.3>).
In order to follow this recommendation, a Postfix MSA (being part of a system DKIM-signing outbound messages) needs to be configured to convert all submitted 8-bit messages to 7-bit (base64 or Quoted-Printable). Is this possible? I found the configuration parameter disable_mime_output_conversion which disables conversion to 7-bit. Its use is proposed as workaround in order to avoid breaking of DKIM signatures of inbound messages if an SMTP-based content filter (not advertising 8BITMIME) is employed (s. <https://www.postfix.org/MILTER_README.html>). Setting ... disable_mime_output_conversion=yes ... for the client delivering to the Internet would prevent to break DKIM signatures of 8-bit emails on delivery to SMTP servers not advertising 8BITMIME but it may not prevent breaking of the signature on deliveries to further hops. (And it does not conform the standard.) Is there some parameter which could have been named enforce_mime_output_conversion in analogy to disable_mime_output_conversion or some other way to configure this? Cheers Stephan _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
