(unknown)

I have the following procmail recipe to auto-respond upon certain
criteria.  The recipe "works" in the way to match and to send reply email;
however the sent email only has mail header without mail body (empty), 
that I could not get it why mail body is "not formed" or "not sent":

SUBJADDR =`formail -xSubject: |perl -pe 's/.*sub.*\s+([^\s]+\ <at> [^\s]+)/$1/sg;s/^\s+//g;s/\s+$//g;'`
HISTMARK = `date +"%s"`

:0
* ^TO.*watchdog <at> my.domain
| (formail -i"Subject: Confirmation needed" \
       -I "To: $SUBJADDR"; \
       echo " "; \
       echo " "; \
       echo "Confirmation mark: $HISTMARK") | $SENDMAIL -oi $SUBJADDR

I tried single or double 'echo " ";' lines to leave 1 or 2 space lines 
between mail header and body - that makes no difference.  Any suggestion 
would be appreciated.

Zhiliang