Arch is cutting edge Linux distro. It is going to be a problem no matter what you do. If I were you, I would make sure daily backups are enabled. Second, you can always check for output pacman command to see if you have any updates available. If so email it.
See if updates available on an Arch Linux box
Maybe something as follows:
pacman -Qu &>/dev/null
if [ $? -eq 0 ]
echo "Updates needed"
echo "No updates needed"
Edit: Of course replace echo with mail command:
mail -s 'Update needed @ $(hostname)' your-email-id < /dev/null