Free Email Tools

Developer tools for email authentication, testing, and deliverability. All free, no sign-up required.

DNS & Authentication

Generate and verify email authentication records

Generate a valid SPF (Sender Policy Framework) TXT record for your domain to prevent email spoofing and improve deliverability.

Look up and verify your domain's DKIM (DomainKeys Identified Mail) DNS record to ensure email authentication is properly configured.

Generate a DMARC (Domain-based Message Authentication) policy record to protect your domain from email spoofing and phishing.

Look up SPF, DKIM, and DMARC DNS records for a domain and see whether email authentication is ready for sending.

Test and optimize your emails before sending

Analyze your email subject line for length, spam triggers, personalization, and effectiveness. Get actionable tips to improve open rates.

Check email copy and HTML for spam-trigger words, risky formatting, suspicious links, and deliverability patterns before you send.

Preview your HTML email template in desktop and mobile views. Paste your HTML and see exactly how your email will look.

Useful email development tools

Validate email addresses by checking format, domain existence, and MX records. Reduce bounces by verifying addresses before sending.

AISend is a transactional email API that helps you send email in 2 minutes with domain setup, delivery tracking, and 3,000 emails/month free.