There are a few ways you can source contact data for use in your outreach program.
IMPORTANT NOTE: What you want to avoid at all costs though is purchasing cheap pre-curated contact lists. These can be a recipe for disaster, so far as their effect on a senders email sending reputation is concerned, because they are often recycled lists that contain things like Spam Traps and outdated contact information.
Here are some alternative ways of generating contact lists for use in Cold Outreach programs - i.e. reaching out to contacts you have no prior relationship with:
Hypadrive.ai integrates with a best in class email validation service so when you upload your contacts into Hypadrive.ai, the validity of their email addresses is checked before sending. Any non valid emails will show error messages. This is done to protect your sender reputation.