[chrislan815]

sounds good but who do you email?

[kqr]

People who are good at something you want to be good at. People who invented or popularised techniques you like. Many of them I've come across have published their emails, if nothing else as a "if you have feedback on this book, reach out to [e-mail]".

[iancmceachern]

You can build your own list (capture emails on a subscription form on your website like I do), some people buy them from people who sell such things (although Im certainly not advocating for this, just answering your question), or use tools like LinkedIn sales navigator, etc.

[cuu508]

Buying and using contact lists is a quick way to ruin any reputation you may have.

[dbtc]

Also you can ask.