R Priority Email Ranking Question/Query

Hello all.

I am looking to compare two different ways of email ranking (Similar to Google's Gmail priority inbox) in the R programming language.

I would like to try and do this using both a linear regression method & decision tree method (Using a free public email corpus).

Ultimately, i would like to rank the emails on priority e.g. using the frequency of emails received from a certain sender.

Is this possible in R?, using the methods i have listed above?.

Thanks,