Email authentication guides
Practical, no-nonsense guides to SPF, DKIM and DMARC. Fix what is broken and keep your mail out of spam.
DKIM Key Rotation: How Often to Rotate Keys Without Breaking Mail
A practical DKIM key rotation guide: rotate every 6 months by default, every 3 months for 1024-bit keys, and monthly for high-value senders. Includes a zero-downtime dual-selector runbook, automated rotation with CNAME-hosted keys, and an emergency procedure for a suspected key compromise, all without bouncing legitimate mail.
Does DMARC Stop Phishing? What It Blocks and What It Doesn't
DMARC at p=reject stops attackers who forge your exact domain, including most CEO-fraud that spoofs your address. It does nothing about lookalike domains, display-name tricks, or a hijacked mailbox that logs in legitimately. This guide gives an honest yes/no matrix, pairs every gap with the control that actually closes it, and shows where DMARC fits in a layered defense so you stop treating it as a silver bullet.
How to Stop Someone From Spoofing Your Email Domain
A step-by-step playbook to stop attackers from sending email as your domain: audit every legitimate sending source, get SPF and DKIM passing and aligned, then move DMARC to a reject policy. Includes what this stops, what it does not (lookalike domains and display-name spoofing), and a free lookup to check your current status.