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
   Mail Tester▲309

   Test the spamminess of your email

   2016 · mail-tester.com · its alternatives →

3. 3
   mailX by mailwarm▲596

   Email deliverability toolkit for humans and AI agents

   May 2026 · themailx.com · its alternatives →

4. 4
   MailDump▲270

   Find, extract and verify emails automatically

   2018 · maildump.co · its alternatives →

5. 5
   Generect Email Finder▲466

   Verify and validate emails at scale

   2024 · generect.com · its alternatives →

6. 6
   Email Spam Checker by Autoklose▲105

   Send spam-free, high-converting emails

   2020 · app.autoklose.com · its alternatives →

7. 7
   Mailnest▲100

   Sandbox Email testing tool for IT product, service companies

   2020 · mailnest.io · its alternatives →

8. 8
   Email List Verify▲330

   Remove hard bounces and email traps from your email lists

   2016 · emaillistverify.com · its alternatives →

9. 9
   MailSlurp▲103

   End-to-end email testing made easy

   2018 · mailslurp.com · its alternatives →

10. 10
    MailCheck▲49

    Stop Free Trial Abuse with Advanced Email Verification

    2025 · mail-check.tech · its alternatives →

11. 11
    MailAdept by mailwarm▲274

    AI Agents & Email deliverability experts on your team

    Jul 2026 · mailadept.com · its alternatives →

12. 12
    Mailivery▲251

    Reach the inbox, not the spam folder

    2021 · mailivery.io · its alternatives →

13. 13
    MailSnag▲83

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

    2018 · mailsnag.com · its alternatives →

14. 14
    Trumail▲215

    Free email verification API

    2017 · emailable.com · its alternatives →

15. 15FS
    Fake SMTP server as a service▲149

    2017 · develmail.com · its alternatives →

16. 16
    mailfloss▲175

    Remove fake and bounced emails without code or spreadsheets

    2019 · mailfloss.com · its alternatives →

17. 17
    KleanMail Free Email Verifier▲177

    Emails inboxed, always.

    2022 · kleanmail.com · its alternatives →

18. 18AF
    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 →

19. 19
    Spam Checker by Mailmeteor▲88

    Detect and remove spam words in your emails

    2022 · mailmeteor.com · its alternatives →

20. 20
    Mailtrap.io▲125

    Fake SMTP. Send Test Emails without spamming real customers

    2014 · mailtrap.io · its alternatives →

21. 21
    MailCue▲82

    Run as a fully hardened production email server.

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

22. 22
    SMTP‑Test.com▲103

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

    2025 · smtp-test.com · its alternatives →

23. 23
    Mailsnag▲31

    Seamless Email Testing and Receiving

    2024 · mailsnag.com · its alternatives →

24. 24
    VerifyRight▲5

    Catch fake emails before they signup

    2025 · verifyright.io · 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 →