How does changing DKIM selectors impact email reputation and what are the best practices for key rotation?

Changing DKIM selectors can impact email reputation, primarily if not managed correctly during key rotation. While some ISPs might track selectors, Google uses IP/selector/domain pairs to identify senders. Experts recommend regular key rotation (every 3-6 months per Google, annually per Reddit, or more often if compromised) to limit the impact of compromised keys. Key findings emphasize that the DKIM selector helps locate the public key and accurate DNS configuration is crucial to avoid authentication failures. Using CNAMEs for selectors facilitates easier changes. Multiple sources suggest that you should avoid reusing keys. Practical considerations include ensuring DNS record propagation, retiring old selectors, considering multiple selectors, monitoring DMARC reports, and testing the new selector. Furthermore, it's important to use longer DKIM key lengths (e.g., 2048 bits) for enhanced security, and some ESPs are transitioning to CNAME DKIM authentication.

Changing DKIM selectors can impact email reputation, especially if not managed correctly. While some providers use the DKIM selector as part of their sender identification, best practices emphasize careful key rotation and selector management. Rotating DKIM keys regularly (at least annually, or more often if a compromise is suspected) is essential for security. When changing selectors, proper propagation of the new DKIM record is crucial, and old selectors should be retired to prevent malicious use. It's also vital to monitor DMARC reports post-rotation to ensure email authentication and swiftly address any issues. Using longer key lengths (2048 bits) enhances security. Testing the new selector and monitoring DMARC reports are crucial steps after DKIM rotation.

Changing DKIM selectors is crucial for key rotation, although some ISPs may have incorrectly used selectors for reputation tracking in the past. Regularly rotating keys mitigates security risks such as unauthorized email sending. Options for key rotation include 'ping-ponging' between two selectors. Avoiding reusing keys and rotating the keys frequently are important. Using CNAMEs simplifies selector changes. Rotating DKIM keys without selector changes is difficult to action and risky if not done infrequently. Longer key lengths, like 2048 bits, enhance security.

DKIM key rotation is crucial for security, limiting the impact of compromised keys. Google recommends rotating keys every 3-6 months. The DKIM selector identifies the public key, and changing it requires updating DNS records. Microsoft provides guidance for key rotation in Office 365. Cloudflare emphasizes proper DNS configuration, including the correct selector, to prevent authentication failures.