Dev tools · alternatives · 2026

24 alternatives to Mailosaur

Automate email and SMS tests using any language or framework

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Mailosaur launched in 2020; newer entries below may have overtaken it.

1. 1
   MailSlurp▲133

   Test, build & automate email and SMS

   2024 · mailslurp.com · its alternatives →

2. 2
   mailX by mailwarm▲602

   Email deliverability toolkit for humans and AI agents

   May 2026 · themailx.com · its alternatives →

3. 3
   Generect Email Finder▲480

   Verify and validate emails at scale

   2024 · generect.com · its alternatives →

4. 4
   Email Spam Checker by Autoklose▲105

   Send spam-free, high-converting emails

   2020 · its alternatives →

5. 5
   Mailnest▲100

   Sandbox Email testing tool for IT product, service companies

   2020 · its alternatives →

6. 6
   MailAdept by mailwarm▲287

   AI Agents & Email deliverability experts on your team

   Jul 2026 · mailadept.com · its alternatives →

7. 7
   MailSlurp▲103

   End-to-end email testing made easy

   2018 · its alternatives →

8. 8
   MailCheck▲49

   Stop Free Trial Abuse with Advanced Email Verification

   2025 · mail-check.tech · its alternatives →

9. 9
   Mailivery▲251

   Reach the inbox, not the spam folder

   2021 · its alternatives →

10. 10
    MailSnag▲83

    Automated email testing for dev/staging/QA/CI environments

    2018 · its alternatives →

11. 11
    Trumail▲215

    Free email verification API

    2017 · its alternatives →

12. 12
    mailfloss▲175

    Remove fake and bounced emails without code or spreadsheets

    2019 · its alternatives →

13. 13
    KleanMail Free Email Verifier▲177

    Emails inboxed, always.

    2022 · its alternatives →

14. 14AF
    A fake SMTP server for software integration testing▲127

    This is a side project of mine. Use this as your SMTP server in a test environment to guarantee that your users don't receive test emails. Looking for feedback, especially on the security side.

    2024 · fakemail.stream · its alternatives →

15. 15
    Spam Checker by Mailmeteor▲88

    Detect and remove spam words in your emails

    2022 · its alternatives →

16. 16
    Mailtrap.io▲125

    Fake SMTP. Send Test Emails without spamming real customers

    2014 · its alternatives →

17. 17
    MailCue▲82

    Run as a fully hardened production email server.

    Apr 2026 · olib-ai.github.io · its alternatives →

18. 18
    SMTP‑Test.com▲103

    One‑click SMTP server test with real‑time protocol logs

    2025 · smtp-test.com · its alternatives →

19. 19
    MailVeri▲7

    Bulk email verification tool

    2023 · its alternatives →

20. 20
    Mailsnag▲31

    Seamless Email Testing and Receiving

    2024 · its alternatives →

21. 21
    VerifyRight▲5

    Catch fake emails before they signup

    2025 · verifyright.io · its alternatives →

22. 22
    Mailerio▲30

    Keep your lists clean with email validation tool

    2025 · mailerio.com · its alternatives →

23. 23
    DisposableCheck – Disposable Email Check▲12

    Free Disposable Email Detector & API

    Jan 2026 · disposablecheck.irensaltali.com · its alternatives →

24. 24
    Mail Tester Tool - By Maileroo▲11

    Test your email deliverability

    2024 · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →