Cold outreach prospecting

HI all,

We are trying to get together a list of potential customers to build our prospecting database and are finding it hard and need some guidance.

Our product https://slyce-io.co.uk/ is quite specific and we need some sort of targeting of users - potentially development managers, database admins, product owners and developers etc that use Azure.

I have looked at LinkedIn Sales Navigator but it looks like you can only mail 50 people per month - I guess to stop spammers etc but this seems pretty limiting if you want to start to promote your product.

I was wondering what other people use? do you use Navigator or some other product - I have heard of hunter.io but are there any others?

Do any of you just go onto groups and connect with people directly from there and is that a successful way to go?

Kind regards
Jerrod