MailDev
MailDev: A free, open-source choice for inspecting application emails during local development. Ranked #16 of 27 in Email Testing Software by our editors (6.9/10); pricing: Free plan; best for local application-email capture and inspection.
At a glance
- Editor score6.9 / 10
- PricingFree plan
- Best forLocal application-email capture and inspection
- Free planYes
- Paid fromFree
- Facts checked20 Sep 2026
Where it wins
- Catches application emails locally before they reach real recipients
- Shows HTML, plain text, headers, raw source, and attachments
- Includes REST API, WebSockets, Docker, and framework integrations
Where it doesn't
- Focused on local development rather than hosted email-client testing
- Does not cover spam, accessibility, or link checks
- SMTP relay is optional and requires additional configuration
Our verdict on MailDev
MailDev is a free, open-source email testing tool for developers who need to capture and inspect messages generated by an application. It runs as a local SMTP server, keeping test emails away from real recipients, and provides a browser-based inbox for reviewing email content. The interface supports rendered HTML, plain-text, header, and raw-source views, along with attachment preview and download. MailDev is available through Docker and npm, with web, API, and self-hosted deployment options.
Its strongest fit is development workflow coverage. The REST API supports listing, reading, searching, downloading, and deleting mail, while WebSocket notifications provide real-time updates. Optional SMTP relay and auto-relay rules extend the workflow when messages need to be forwarded. Integrations include SMTP, Nodemailer, Django, Ruby on Rails, Laravel, and Docker. An optional MCP server provides AI-agent access to the inbox, adding a programmatic path for AI-assisted workflows without changing MailDev’s core local-email focus.
MailDev’s scope is deliberately narrower than a hosted email-client testing service. It is well suited to checking whether an application generates the expected content, headers, source, responsive rendering, and attachments during development. It should not be the first choice for teams that need spam testing, accessibility checks, or link validation. Developers seeking a free local capture tool with API and automation options should find the feature set aligned with that task; teams needing broader email-quality validation should choose a product built around those additional checks.
Your product? Our editors can test MailDev in depth and publish a review, labelled as paid · from $149/mo →
MailDev pricing
MailDev fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Email clients | Not verified |
| Device coverage | Not verified |
| Spam checks | Not verified |
| Accessibility checks | Not verified |
| Link checks | Not verified |
| Inbox testing | Not verified |
| API access | Yes |
| Deployment | Self-hosted |
| Platforms | Web |
| Support | Docs |
| Built for | Solo, Small business, Mid-market (editorial estimate) |
| Integrations | 6 integrations: SMTP, Nodemailer, Django, Ruby on Rails, Laravel, Docker |
| Pricing | Free plan |
| Website | maildev.github.io |
| Facts checked | 20 Sep 2026 |
MailDev integrations
MailDev lists 6 integrations on its own site.
- SMTP
- Nodemailer
- Django
- Ruby on Rails
- Laravel
- Docker
Alternatives to MailDev
- LitmusBroad pre-send email QA with previews, testing, monitoring, integrations, and APIs.9.3
- Twilio Email TestingA flexible email-testing option with a free trial, rendering checks, spam tests, and API access.8.8
- GlockAppsA broad deliverability toolkit for inbox placement, reputation, authentication, and alerts.8.5
See all MailDev alternatives →
Used MailDev? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used MailDev for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
MailDev is listed in our Email Testing Software directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/maildev/"><img src="https://www.itechguides.com/best/badge/maildev.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update