Use a dummy SMTP-based after-queue content filter to force 8->7
conversion, then DKIM sign the message with the smtpd+cleanup+milter
after the filter.
[Sorry, no ASCII art. Responding over a verry slow 3G link]
Wietse
Hello,
again I struggled about the 8BITMIME SMTP-Extension. The RFC - initial
version published in 1993 -
is not as widely adopted as one may expect. In fact even largest
mailprovider do not announce 8BITMIME.
That forces any RFC conforming MTA to reject or convert the message
into valid 7-