Your Events are on open and on post reload only so the alert shall only come up during these events, on open i dont think this will work as nothing is selected when the document is opened therefore your condition wont be met. The same is for the On post reload as every selection sometime clears after the reload.
I suggest you do a macro for pop up message so that it can pop up whenever a selection results into a less than 10 revenue.
configure your servere for mail sending
setting(tools)--->alert(you can add multiple alert)
better option for is put conditions in script only (rev>0)
and write 1=1 in condition field.
Content in Message field ( its working tike text field in qlikview it allow you to write condition)
aways try to write a batch for email sending (check option Batch) .
dont go for interactive becoz it will send one mail more than one time