Comment 29 for bug 316272

In my testing this seems to now be working, subject to some conditions:

 * not for mail to <email address hidden> (bug 643219)
 * the From address must be in the signing domain (eg at gmail.com not elsewhere) (bug 643223)

Also

 * dkim whitelist should be in configuration (bug 643224)
 * error messages and user documentation should mention dkim (bug 643225)

and barely relevant

 * bug 387327, dkim-sign outgoing mail