On Wed, Sep 06, 2023 at 01:33:30PM +0200, f...@igh.de wrote: > Dear Mutt Users > > recently I experienced DKIM fails that depend on the > Content-Transfer-Encoding of messages text part. > > Being a german I use to write my messages in german with UTF-8 > encoding. I prefer plain text. My e-mails are DKIM signed. I have > checked DKIM to be set up correctly twice. > > By default Mutt does 8bit encoding for text/plain. Now I found that > several (most) of the recipient systems fail to check DKIM. > > If I force Mutt to change the encoding from 8bit to 7bit, base64, or > quoted-printable (using ^E in the compose menu), the DKIM checks > succeed. > > Can I force Mutt to use quoted-printable or base64 by default for > encoding of plain text? > > Does anyone have similar experiences? Is there an explanation for this? > May there be any interference with the MTA? > > Interestingly DKIM checks do not fail if I use non-ASCII characters in > the subject. Also attachements do not cause DKIM to fail. > > Best Regards > > T. Finke > > -- > ------------------------------------------------------------------------ > T. Finke > f...@igh.de > ------------------------------------------------------------------------
Hi, This has come up recently in the Postfix mailing list. MTAs can convert 8bit messages when sending to another MTA that doesn't advertise that it can accept 8bit. If the DKIM signing happens before the conversion, then subsequent DKIM checks will fail. Work is being done in Postfix to address this. I don't know about other MTAs. It seems unlikely that there are any MTAs that can't accept 8bit messages, but perhaps there are some that are misconfigured and don't advertise the fact to other MTAs. cheers, raf
