MailTester.ai

MailTester.ai checks whether a newsletter or email campaign is likely to reach the inbox. You forward a test email to a one-time test address provided on the site, and the tool analyzes the subject line, content, links and authentication signals. It returns a deliverability score (0-100), a verdict, a forecast of where the email lands at Gmail, Outlook and Yahoo (Primary, Promotions or Spam, with confidence), and three prioritized fixes. The site says it is built for senders on Beehiiv, Kit, Substack and Mailchimp, and lists Klaviyo and Brevo as other platforms where a test send can be forwarded. Paid credits add AI deep-dives, including subject, body and CTA rewrites. The site also lists SPF, DKIM, DMARC and SMTP tools, and states it is EU-hosted, GDPR-oriented and deletes data automatically. It does not verify subscriber address validity.

Key features

• Forward a test email to a one-time test address to get a report
• Deliverability score out of 100
• Predicted inbox placement (Primary, Promotions or Spam) for Gmail, Outlook and Yahoo with confidence level
• Plain-English verdict
• Three prioritized fixes to improve deliverability
• Checks subject line, content, links and authentication
• AI rewrites of subject, body and CTA (included in paid bundle)
• Authentication tools listed on site: SPF Checker, DKIM Analyzer, DMARC Validator, SMTP Tester
• EU-hosted, GDPR-by-default, automatic data deletion, no third-party trackers

Best suited for

• Newsletter senders on Beehiiv, Kit, Substack or Mailchimp
• Senders on Klaviyo or Brevo who can forward a test send
• Checking a campaign for Promotions or Spam placement before sending to a list

Pricing

Free plan: €0 for unlimited scoring. Credits: €5 one-time for 500 credits (5 AI deep-dives per the site). Starter: €9.99/month for 1,100 credits. Pro: €19/month for 2,500 credits.