Best Email Testing Software in 2026
Updated
In short: Twilio Segment is ranked #1 of 28 as of 4 October 2026, ahead of GlockApps and Mailpit. The best-ranked option with a free plan is GlockApps. The lowest first paid tier on this page is Unspam.email at $5/mo.
Checking an email before it goes out can involve rendering, inbox placement, links, and accessibility. Compare email-client and device coverage with inbox testing, spam checks, and link checks to see which review needs are represented. API access may matter if you want to connect testing to other tools, while the free plan and starting price help frame availability and cost. GlockApps and Emailens head the ranked entries, followed by MailSlurp and Litmus. Mailosaur, EmailQA, Unspam.email, and RenderOps also appear among the first options. Use the listed criteria to focus on the kinds of checks that matter for your email work.
28 email testing software ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
#1 Twilio Segment Top pick · 7.9 Free plan · $120/mo #2 GlockApps Runner-up · 7.6 Free plan · $59/mo
#3 Mailpit Also great · 7.2 Free plan · Free
- Free planFree trial WebiOSAndroid
- Free plan
- Yes
- Paid from
- 15 /mo
- Device coverage
- both
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$120/mofirst paid tier About Twilio SegmentVisit site - Free planFree trial apiWeb
- Free plan
- Yes
- Paid from
- 59 /mo
RecognisedDocumentedFree planFree trialPlatforms$59/mofirst paid tier About GlockAppsVisit site - Free plan apiLinuxmacOSself-hostedWebWindows
- Device coverage
- both
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan apiWeb
- Free plan
- Yes
- Paid from
- 19.99 /mo
- Email clients
- 2 clients
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$19.99/mofirst paid tier About MailSlurpVisit site - Free plan apiWeb
- Free plan
- Yes
- Paid from
- 7 /mo
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$7/mofirst paid tier About SMTP LabsVisit site - Free plan apiextensionWeb
- Free plan
- Yes
- Paid from
- 9 /mo
- Email clients
- 21 clients
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$9/mofirst paid tier About EmailensVisit site - Free trial apiextensionWeb
- Free plan
- No
- Email clients
- 100 clients
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$99/mofirst paid tier About LitmusVisit site - Free plan Web
- Free plan
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free trial apiWeb
- Free plan
- No
- Paid from
- 20 /mo
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$20/mofirst paid tier About MailosaurVisit site - Web
- Free plan
- Yes
- Paid from
- 15 /mo
- Device coverage
- both
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$15/mofirst paid tier About Twilio Email TestingVisit site - Web
- Free plan
- No
- Email clients
- 120 clients
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$312.50/mofirst paid tier About Inbox MonsterVisit site - Web
- Free plan
- No
- Paid from
- 39 /mo
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$49/mofirst paid tier About SendForensicsVisit site - Web
- Free plan
- Yes
- Paid from
- 20 /mo
- Email clients
- 11 clients
- Device coverage
- both
- Spam checks
- No
- Accessibility checks
- No
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Paid from
- 79 /mo
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Paid from
- 10 /mo
- Email clients
- 21 clients
- Device coverage
- both
- Spam checks
- Yes
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - WebWindowsmacOSLinux
- Free plan
- Yes
- Device coverage
- both
RecognisedDocumentedFree planFree trialPlatforms - Free plan apiWeb
- Free plan
- Yes
- Paid from
- 14 /mo
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms$17/mofirst paid tier About Mailtrap Email SandboxVisit site - Web
- Free plan
- Yes
- Paid from
- 29 /mo
- Device coverage
- both
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Device coverage
- both
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Paid from
- 9 /mo
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Paid from
- 10 /mo
- Accessibility checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan apiLinuxmacOSself-hostedWeb
- Free plan
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- Yes
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Web
- Free plan
- No
- Spam checks
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan apiWeb
- Free plan
- Yes
RecognisedDocumentedFree planFree trialPlatforms$5/mofirst paid tier About Unspam.emailVisit site
Is your platform on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which email testing software is ranked first on The Geeks Club?
Twilio Segment is ranked #1 of 28 with a score of 7.9. GlockApps is second and Mailpit third.
How many of these have a free plan?
10 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Unspam.email has the lowest first paid tier we found: $5/mo.
How is this list ranked?
Ranked on how quickly a newcomer can get going: documentation depth, a free tier or trial, and the platforms it runs on. Paid placements never change a rank.