If by cold mailing, you mean cold emailing, then no it's not dead. Matter of fact, the most successful companies rely on cold emailing as their main sales channel.

Cold emailing receives a bad rep, but it is still the most effective way for outbound sales. There's nothing more better than engaging and warming up the conversation with your prospect through cold e-mail. The problem is that most people cold email incorrectly which results in a spammy email.

The goal is to be direct and keep it short. Don't send long templates that people don't want to read. Don't send email with misleading subject lines etc.