Quota notifications

I am setting up some quotas on Isilon cluster. Setting quotas themselves is kind of self explanatory: Hard, Soft, Advisory etc. What confuses me are notifications.

First of all - how "Notify owner" is working? For example - I would like to setup bunch of department shares and apply directory quotas on them. So, can I set Settings that it would notify owner? But, then how do you define owner on quota, where is it coming from?

And what exacly email mapping does??? So, I have AD users accessing files on Isilon. Their AD username is User@ad.domain.com, but email addresses are like Name.Surname@domain.com. Email mapping - from what to what is being mapped? What AD attributes are being looked at/mapped?