Mromat on "Import subscribers' list"

Hi everybody,
I'm about to launch a Blog, and I would like to know if it's possible to import subscibers, so that they can receive new posts notifications.
I have a database of 1500 contacts I'm already using to send out newsletters, and I would like to import this database of contacts as WordPress subscribers.
Is it possible?
Is there some plugin giving this possibility?

Thank you in advance for your support,

Mélanie

via Chebli Mohamed