Support has recently been added in the Exim development tree
for UTF-8 in email envelopes. It has not hit a released
Exim version yet.
For the technical, this is the SMTPUTF8 extension defined
in RFC 6530 et. al.
Details are in the experimental.txt documentation.
People interested in trying this in a production environment
will need to compile from source, with EXPERIMENTAL_INTERNATIONAL
defined. Feedback would be very welcome as the systems I
can run it on are unlikely to see much internationalized
traffic.
The Exim sources are available from
git://git.exim.org/exim.git
The bug for SMTPUTF8 specifically is
http://bugs.exim.org/show_bug.cgi?id=1516
and the umbrella bug for internationalization is
http://bugs.exim.org/show_bug.cgi?id=1177
--
Jeremy
