Comment 1 for bug 265945

Changing line 200 of the mm-handler Perl script from:

    $list = $addr;

to read:

   $list = lc $addr;

will fix this problem.

mm-handler is an unsupported contribution and has other
potential
problems which can lead to mail loss.

There is an alernative Python implementation of this
approach which is more tightly integrated with MM and does
not have the same defects: see MM patch #64481