I have been trying to look into amavisd-new given this interesting thread.What I think is happening is when amavisd-new will not advertise 8BITMIME and as a result, Postfix will convert the message body to a 7-bit encoding format such as quoted-printable or base64 if the message contains 8-bit data.. (ie. non-ASCII characters or binary data).
So the SMTP dialog might look like this when the above directive is commented out.The code was a little difficult to read so I could still have this wrong but I believe if you commented that line out, you would not get this conversion to 7-bit if that is what you are after. I don't seem to have much breakage here but there has been the odd email that I have seen from time to time but it is very infrequent.
I was under the impression that you want it to be 7-bit before signing which why the default in amavisd-new I suspect to minimize the chances of breakage during transit. Ref: https://datatracker.ietf.org/doc/html/r ... ection-5.3
Jim
Code:
smtpd_discard_ehlo_keywords => ['8BITMIME'],So the SMTP dialog might look like this when the above directive is commented out.
Code:
Client: EHLO example.comServer: 250-amavisd-new.example.com 250-8BITMIME 250-SIZE 104857600 250-STARTTLS 250-ENHANCEDSTATUSCODES 250 PIPELININGI was under the impression that you want it to be 7-bit before signing which why the default in amavisd-new I suspect to minimize the chances of breakage during transit. Ref: https://datatracker.ietf.org/doc/html/r ... ection-5.3
Jim
Statistics: Posted by JDunphy — Fri Mar 14, 2025 11:36 pm