Bitnami runs a monthly contest[0] where you can vote for your favourite application to be packaged. I couldn't find an entry for Dada Mail, but you can go ahead and submit it for review[1] and we can add it to the contest.
The winners are first the users, who have an easier way to install the app (it's already given away for free) and you, which are given another solid app to offer.
I don't really get anything by entering the app in a contest. I'm not really interested in contesting the app at all. But, to give your users more choice on what to use? Again a total win for you.