Fwd: esmtp-run delivers mail from shell, but not from nagios

[Jesse Thompson <jesset@gmail.com>]

I hope this is the right place to ask this question; #debian irc
directed me here since esmtp-run doesn't appear to have it's own list.

I'm fairly sure I have isolated this problem as being related to
esmtp-run and not directly related to nagios. Nagios takes a string
and executes that via popen in order to send email notifications, and
can execute any other arbitrary commands I try but not esmtp-run's
simple email sender. Futhermore I've used nagios' debug log to confirm
the command runs as expected, using the expected string (after macro
expansions, etc) and that a zero return value is rendered from
esmtp-run indicating no errors: yet no delivery happens either.

The test command I am using is:

/bin/echo "testing" | /usr/lib/sendmail -f my@email.com my@email.com

I've confirmed that the nagios daemon attempts to run this command via
user "nagios", and I can run that exact string from shell when "su -
nagios" to impersonate that user, and receive the remotely delivered
email, but when run through the daemon no action is taken that I can
detect. I do not have "mda=" configured, since I want no local
delivery, remote only. I can see nothing in /var/syslog, and know of
no other logging facility esmtp-run might want to use. I have added a
"preconnect" line to emulate logging, and that line appears to
function when I invoke from shell and not to function when invoked
from nagios. I have checked /var/mail/ and see no new activity, in
case procmail were being somehow invoked and dumping messages there.

Here is my /etc/esmtprc:
hostname=email.email.com:25
preconnect='/bin/date >> /tmp/test2'

So I don't know if this is related to the daemon somehow having
incompatible environment variables, or what could be different about
these methods of invocation or what to test next save tearing apart
the source code and gdbing everything that moves. If there are any
esmtp-run experts out there, or just
reliable-send-only-MUA-that-plays-nice-with-nagios experts, I could
use some pointers. :)

Thanks guys!

- - Jesse