OK, solved it. With thanks to Robert Elz. Quite simply, I just use a inetd.conf entry sitting on the local sendmail submission port (why don't we have an /etc/services entry for this new sendmail port?): 127.0.0.1:587 stream tcp nowait root /usr/libexec/sendmail/sendm ail sendmail -Am -Lsm-mta -bs R.