Disabling inbound email in a jail

[Kirk Strauser]

I only want sendmail in a jail to do one thing: forward nightly reports from root at localhost to a real account on another 
machine.  What's the proper way to configure this?  By default, sendmail_enable="NO" in /etc/rc.conf still gives a 
running sendmail that accepts mail from other hosts:

me at realhost$ echo foo | mail me at jail.example.com

me at jail.example.com$ tail -f /var/log/maillog
Feb 27 09:43:37 jail.example.com sm-mta[86832]: n1RFhbBp086832: from=<me at realhost>, size=735, class=0, 
nrcpts=1, msgid=<20090227154335.877A442071 at realhost>, bodytype=7BIT, proto=ESMTP, daemon=Daemon0, 
relay=jail.example.com [10.0.5.70]
Feb 27 09:43:37 jail.example.com sm-mta[86833]: n1RFhbBp086832: to=<me at jail.example.com>, delay=00:00:00, 
xdelay=00:00:00, mailer=local, pri=30983, relay=local, dsn=2.0.0, stat=Sent

However, if I set sendmail_enable="NONE", then I can't send outbound email either:

me at jail.example.com$ echo foo | mail me at realhost
me at jail.example.com$ tail -f /var/log/maillog
Feb 27 09:37:37 jail.example.com sendmail[86513]: n1RFbbg3086513: from=me, size=28, class=0, nrcpts=1, 
msgid=<200902271537.n1RFbbg3086513 at jail.example.com>, relay=me at localhost
Feb 27 09:37:37 jail.example.com sendmail[86513]: n1RFbbg3086513: to=me at realhost, ctladdr=me (1001/1001), 
delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30028, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, 
stat=Deferred: Connection refused by [127.0.0.1]

What's the happy medium between "sendmail wide open" (eg sendmail_enable="NO" (WTF?)) and "disabled mail 
system" (eg sendmail_enable="NONE")?
-- 
Kirk Strauser