Hello. Wietse Venema wrote in <4m7by01gfjzj...@spike.porcupine.org>: |Matus UHLAR - fantomas: |>>Matus UHLAR - fantomas: |>>> On 17.08.22 13:45, Andy Beverley wrote: |>>>>This is an interesting point that I hadn't thought of. I have |>>>>smtputf8_enable set to yes, but I have just checked the remote server |>>>>and it only shows: |>>>> |>>>>250-AUTH PLAIN LOGIN |>>>>250-STARTTLS |>>>>250 HELP |>>>> |>>>>So are you suggesting that what might be happening is that the email |>>>>is being DKIM-signed as an 8-bit message (with the opendkim milter), |>>>>and then after the signature has been added that the content is then |>>>>altered in order to be delivered as a 7-bit message? |> |> On 17.08.22 10:49, Wietse Venema wrote: |>>This has nothing to do with SMTPUTF8. |>> |>>You might work around this by settting |>> |>> disable_mime_output_conversion = yes |>> |>>in main.cf. |> |> won't this stop mail from being deliverable to the other side? | |Then it would have a different name. | |This setting has been a workaround for SMTP-based content filters |that don't announce 8BITMIME support.
This thread is interesting to me since i have on my (too long) to-do list the desire to write a DKIM thing (the only of those things that i think are good ones). I wonder all the time because RFC 6376 explicitly says Some messages, particularly those using 8-bit characters, are subject to modification during transit, notably conversion to 7-bit form. Such conversions will break DKIM signatures. In order to minimize the chances of such breakage, Signers SHOULD convert the message to a suitable MIME content-transfer encoding such as quoted-printable or base64 as described in [RFC2045] before signing. Such conversion is outside the scope of DKIM; the actual message SHOULD be converted to 7-bit MIME by an MUA or MSA prior to presentation to the DKIM algorithm. Which is why i thought (once i looked a couple of months ago) i _enforce_ postfix to do the conversion for me by not announcing 8BITMIME in the filter. (By then i thought something like milter for verification and filter for generation, iirc.) --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt)