information/thoughts on email/list operations

Hi. Looking to test an app to send a bunch of emails to the college community -- ~5-10k. Assuming the emails addresses will be legit/unique. Trying to talk to anyone who may have set up something like this, or rolled your own? What's the cheapest service you've used? can AWS work in this situation? Do you have anythoghts on 3rd party email validation processes/costs? Net searches gives some insight, but thought I'd post here as well. thanks.