Hi Screwdriver.dll,
A bit simple but if you don't monitor your email out of hours (which I would of thought most sysadmins did) you can send notifications to one or more email addresses if you separated by commas under:
Settings >> Email >> Notifications. Why not have these sent to an inbox that you can gain access to outside of these hours ?
I would also take a look and see what options your ITSP offers you from their platform, you might find what you are looking for here. Any reputable ITSP should have a pretty decent interface with plenty of options for this.