If your budget is tight, here are three quick ways to find emails for free:
Clearbit Connect is a Gmail and Outlook add-on that looks for a person’s email from a variety of sources as well as their own database (related: check out the best Gmail add-ons and extensions to improve your productivity).
GetProspect is a Chrome extension that allows you to find someone’s email address by their name and domain.
RocketReach can quickly find emails for you, especially if your target is fairly high profile. Just sign up for a free account and start email hunting.