I use three programs to find email addresses and they are all free:
Clearbit for Gmail – great program! You type in a URL and it pulls emails addresses. You can search by seniority – role or name
If Clearbit isn’t finding what I need I use hunter.io – search by URL and names
Last – I use snov.io – it has a ton of features and its pretty new
How do I find my targets? Usually on their websites. Look under the “About” or “Contact” tabs for the executives of the company. I also hit the Chief Marketing Officer sometimes called the CMO. If you cant find them on their website just Google the executives names. Linkedin is always a great resource.
It never hurts to ask for a referral. If someone replies they are not interested ask them if they know anyone who may need the name. Also, many large companies have no idea who each other are or their division does not deal with domain names. For instance, I was emailing people at facebook and I received a reply that they weren’t interested. I asked who handled domain name buying and they gave me her address! It doesn’t hurt to ask.
I also search for startups on Angel list – Y Combinator and Google startups for the names you want to sell. You will usually find something in your industry.
Hope this helps – happy hunting. If you want to share any tips or tricks let me know and I will post you as a contributor.