Email Available Updates for Debian

Before you proceed below please check:

• Simple apt daily update script, see here.
• Configure exim4 to send messages by smarthost, no local mail, see here.

We are going enhance daily update script by ability to send a list of new updates to mail.

#!/bin/sh

mailto=debian-updates@dev.local

# Download only; package files are only retrieved, not 
# unpacked or installed.
apt-get -dqq update
apt-get -dyqq upgrade

has_upgrades=$(apt-get -s upgrade | grep ^Inst)
if [ "$has_upgrades" ] ; then
    echo "$has_upgrades" | mail -s \
    "Updates for $(hostname) on $(date +%Y-%m-%d)" \
    $mailto
fi

Alternatively consider using apticron, read more here.