DKIM

What is DKIM?

DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email, a technique often used in phishing and email spam. DKIM allows the receiver to check that an email claimed to have come from a specific domain was indeed authorized by the owner of that domain.

Configure DKIM

Do this for each of the domains you will use for cold emails.

If you are using Google Workspace you can follow these instructions, they are well documented and easy to follow (just read through them first).