E-mail blast

I don't know if this is the right section for this. I have 48k new e-mails I harvested from a site in my niche. I don't know how active these e-mails are so the blast i am going to send is basically a test. I was wondering if anyone knew a cheap or free way to send an email to all 48k emails. I don't want to pay 500 or so dollars on a gamble. Any info or advice would be greatly appreciated.

THANKS!

Amazon web service allow you to send 2k emails per day for free.