Using Piping in a script

Just to document it, since i forget those things easily.
Below is an example email script based on sendmail.
The cat command will read anything coming from a pipe to the MESSAGE variable.

mail.sh:

# send am email to alert if something is not working
MESSAGE=`cat -`

/usr/sbin/sendmail.sendmail -i -t << ENDL
From: "Alert" <admin@khofo02.beren.tst>
To: <sherif.abdelfattah@beren.tst>
Subject:${1}

${MESSAGE}
ENDL