Target the Right Audience
As with anything connected to marketing, understanding and targeting the right audience is key to success.
If you rely on other tactics to reach your target, such as spontaneously just emailing people from an old client list, you'll never be receiving results.
The success of cold emailing relies heavily on the type of person you wish to reach out to.
In other words, they need to be someone who will benefit from your product.
They also need to be a decision-maker, one who will be willing to engage in business propositions with you.
If you're reaching out to businesses, contact the owner or the right point person directly. If you're unsure as to who to target, it's best to label your email body accordingly.
Ask them to lead you to the person in charge, as this increases your chances of reaching the decision maker.