Possible to run workflow from site for all items uploaded?

Hi,

Is it possible to run (site) workflow which can cover all libraries (existing and new)? What we are trying to do is, get an email if user uploads a file to current months' library or future months' library (which aren't created yet)

So we are trying to house the workflow at site level and trying to initiate it from there on. Kindly let me know possible ways of doing this (or if this is impossible). Thanks!