MailGenius (and similar free testers like mail-tester.com) take a one-shot snapshot: send a test email to a generated address, get back a score covering authentication, content, and basic blocklist checks. It's a useful one-time diagnostic — when someone says 'my email lands in spam', a MailGenius score is the fastest way to see whether the basics are wrong.
MailerMonk is a continuous monitor, not a single-shot tester. We don't grade individual messages; we watch your sending domain's authentication, reputation, blocklist status, and inbox placement over time and alert when something changes. The two are complementary — run a MailGenius test when you want to spot-check a specific message; use MailerMonk when you want to know the moment your domain gets blocklisted at 3am.
Feature comparison
| Feature | MailerMonk | MailGenius |
|---|---|---|
| Continuous deliverability monitoring | Yes | No |
| Single-message deliverability test | No | Yes |
| DMARC report ingestion + parsing | Yes | No |
| Continuous blocklist monitoring | Yes | No |
| Real-time alerts | Yes | No |
| Free DMARC / SPF / DKIM / MX checkers | Yes | Partial |
| Free to use MailGenius is free; MailerMonk has free tools but monitoring is paid. | Partial | Yes |
Choose MailGenius when…
- You need a one-shot 'why is this specific email going to spam' diagnostic.
- You don't need continuous monitoring and don't want a paid subscription.
- You're sending so few messages that a manual test before each batch is feasible.
Choose MailerMonk when…
- You want to know the moment your domain is blocklisted, not the next time someone runs a test.
- You send enough mail that 'spot-check before each campaign' isn't realistic.
- You need DMARC report parsing — MailGenius doesn't ingest DMARC reports, it grades a single sent message.
Pricing
MailGenius is free. MailerMonk's free tier includes the DNS checkers; continuous monitoring is paid.
See MailGenius pricing →