DKIM (DomainKeys Identified Mail) is an email authentication method that helps prevent email spoofing and phishing attacks. It works by adding a digital signature to your outgoing emails, allowing receiving servers to verify that the message actually came from your domain and wasn't altered during transit.

Setting up DKIM involves three main steps:

• Generate DKIM Keys - Create a public/private key pair through your hosting control panel
• Publish Public Key - Add a TXT record to your domain's DNS with the public key
• Configure Your Server - Enable DKIM signing on your mail server

The DKIM signature includes several important components that receiving servers check:

• Domain - Which domain sent the email
• Selector - Identifies which key was used (often "default" or "dkim")
• Timestamp - When the email was signed

Proper DKIM setup significantly improves your email deliverability and helps your messages avoid spam folders. Most email providers (like Gmail, Outlook, Yahoo) give preference to emails with valid DKIM signatures. After setup, always verify your configuration using free online tools that check if your DKIM records are properly published and working.

Remember that DKIM works best when combined with SPF and DMARC policies for complete email authentication. These three technologies together create a robust defense against email fraud and improve your domain's reputation with email providers worldwide.