What is DKIM?
DKIM stands for DomainKeys Identified Mail. It is a method of email authentication that allows senders to prevent email content from being altered during the delivery process.
It’s based on public key cryptography, and it works by adding a digital signature to the message header. When the receiver gets an email with DKIM, they check the digital signature to make sure it is valid. If it is, then they know the message has remained unaltered during the transfer.