Since your tags include supply chain management, I wonder if that is the area in which you plan to do your research?

In any case, usually if your research is specific to certain topic area, you can purchase a list, or you may be able to obtain one via a membership organization or other existing organizing / coordinating organization (because they may have privacy agreements with those who provided their email address, they may require you to send through them, and often want something in return - first access to results for their members, etc).

If you just need people, you might also try Amazon's Mechanical Turk: https://www.mturk.com/

Depends on vendor- otherwise, you can purchase emails from advertisers.

Hope this helps

Matt

Since your tags include supply chain management, I wonder if that is the area in which you plan to do your research?

In any case, usually if your research is specific to certain topic area, you can purchase a list, or you may be able to obtain one via a membership organization or other existing organizing / coordinating organization (because they may have privacy agreements with those who provided their email address, they may require you to send through them, and often want something in return - first access to results for their members, etc).

If you just need people, you might also try Amazon's Mechanical Turk: https://www.mturk.com/

I also have good experiences with Amazon's Mechanical Turk, but you need to take into account that most likely this is a convenience sample which might have a bias. If you need domain-specific knowledge, the best approach would be to partner with an association which has a membership directory. If you just contact the survey participants out of the blue, your response rate might be really low. A strong partner might help you to increase it.