Getting distinct values for multiple columns

Hi 

I tried looking through previous threads, but I'm not sure what exactly what I'm looking for would be called. 

I have a table with several columns, but I'm concerned with two of them: BundleID (a number associated with a "bundle" of files) and UserEmail. I'm trying to find out a way to count how many distinct UserEmails have downloaded distinct BundleIDs--how would I do this?

Thank you for your time!