Concept

DKIM (DomainKeys Identified Mail) is an email authentication method that allows the sender of an email to associate their domain name with the email message. This allows the recipient’s email server to check that the email message is authorized by the sender’s domain and has not been tampered with during transit. DKIM uses cryptographic signatures and public-key cryptography to verify the authenticity and integrity of email messages. When an email is sent, the sender’s mail server generates a digital signature for the message, which is then added to the email’s headers. The recipient’s mail server retrieves the sender’s public key from a DNS record and uses it to verify the signature. If the signature is valid, the recipient’s mail server can be confident that the email is from the domain it claims to be from and has not been altered in transit. ...

SMTP stands for Simple Mail Transfer Protocol. It is a protocol used for sending email messages between servers. Most email systems that send mail over the Internet use SMTP to send messages from one server to another, and to deliver messages to local mail clients like Microsoft Outlook or Apple Mail. An SMTP server is a computer that is responsible for sending and receiving email messages. It uses the SMTP protocol to communicate with other email servers, to receive messages from local clients, and to deliver messages to local clients. ...