DKIM (DomainKeys Identified Mail) is an email authentication method that helps secure the integrity of messages and verify the authenticity of the sender. In this article, we'll explore the settings for DKIM that are crucial for effective protection of email communication against attacks such as phishing and spoofing.
1. Generating a DKIM Key Pair
The first step in setting up DKIM is to generate a pair of keys (public and private). The public key will be published in the DNS record of the domain, while the private key will be securely stored on the email server. To generate the keys, you can use tools like OpenSSL or specialized DKIM generators.
2. Publishing the Public Key in DNS
The public key must be published in a TXT record in the DNS of the domain. The record should contain a name, usually corresponding to the DKIM selector, and a value that includes information about the public key and other DKIM parameters. An example record:
default._domainkey.yourdomain.com TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqG..."
3. Configuring the Email Server
The email server must be configured to add a DKIM signature to the headers of outgoing emails. This process involves obtaining the private key and setting up rules for signing messages. Server solutions like Postfix, Exim, or Microsoft Exchange offer various options for integrating DKIM.
4. Setting the Selector and Policy
The DKIM selector allows you to define which key should be used for signature verification. This is useful if you want to have multiple keys for different purposes or departments. You can also define a DKIM policy (referred to as DKIM Policy) that determines how strict the checks should be performed by receiving servers.
5. Monitoring and Analyzing DKIM Records
After implementing DKIM, it's important to monitor and analyze the effectiveness of the settings. This includes tracking authentication reports of messages sent using the DMARC protocol. These reports will help you identify potential issues and optimize the DKIM settings.
Proper DKIM setup is key to securing email communication and protecting against unwanted attacks. Follow these steps to ensure that your emails are authentic and trustworthy.
