Yes, quite a few providers send out emails to people. One person I found on Fiverr. Another was via ...oh bummer....advertize I think it's called. Many different companies will provide ad space in emails and all you have to do is pay them to target the ad for you.
Safe-swaps.com If you want to build your own list, create a squeeze page where you would have your affiliate information and ask them to put in their email and etc. Then in the email send them to your twitter link. This way you building your own list and getting referrals in.
Hi, I would agree with @Alyssa Lochmore about Fiverr. Outside of Fiverr, you can do a search on "Sponsored Email" and you'll find various companies that provide that service. Expedia.com is one of the companies that shows up and you can just imagine how many people they are able to reach by email. Hope this helps.
You can buy their email list and send email yourself. Why do you wan them to send email for you? Just make them an offer to buy their verified email list.
You can use solo ads where you have a person with a big list and they send out your offer and you can also do ad co-ops you can google solo ad directory or list and you will find a bunch. I would list them but I need more likes to post links.
You're talking about buying a solo ad, i think. Best place is safe-swap.com or try typing "your niche" + "solo ads" and gave a look at what's best. Az