Be careful emailing cold leads
Emailing people who have no relationship with your organization can permanently damage your deliverability and get you blacklisted by providers like Google, Microsoft, Yahoo, and Comcast.
When you are trying to grow, a ready-made list of leads can look tempting. You might find a directory, buy a list from a broker, or get access to a strategic partner's audience. Without a business relationship with those people, you are likely to see many bounces, unsubscribes, and spam complaints.
Why cold lists are risky
Emailing people who have not given you permission and do not know you is spam. High bounce, unsubscribe, and complaint rates signal that to email providers, and the damage to your sending reputation can be lasting.
If you must use a cold list
Using a list of people who do not already have a relationship with you is not recommended. If you still proceed:
Go very slowly. Do not send to the entire list at once. Blasting a cold list is the fastest way to be labeled a spammer.
Validate the addresses first. Run the list through an email validation service to remove obviously bad addresses. Validation is not foolproof, but it reduces obvious failures.
Use a warm introduction instead
When the list belongs to a strategic partner, have the partner send the introduction from their own list. Include a link to your website so people can connect with you on their own.
That approach does not put your email reputation at risk, and a warm introduction from someone they already know goes much farther than a cold email from an unknown sender.