head to head
Mailpit vs MailHog
Active maintenance versus a popular tool that stopped getting updates.
What matters for teams building autonomous agents
An agent stack treats email as a two-way primitive. Inbound has to arrive as structured JSON a tool call can consume, sends have to be safe to retry when a model loop repeats itself, and every action needs an audit trail. A provider without inbound parsing only solves half the problem.
| Priority | Mailpit | MailHog |
|---|---|---|
| Inbound parsing | No | No |
| Idempotency keys | No | No |
| Webhooks | No | No |
| Operating since | Not published | Not published |
| Event stream | No | No |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Batch sending | No | No |
| SDKs | None | None |
| Multi-tenant | No | No |
For an agent that reads and writes email running inbound parsing into tool calls and model-generated sends that must not duplicate, the two are level on every priority that can be scored here, so the choice comes down to price and to which product your team would rather operate. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Mailpit | MailHog |
|---|---|---|
| Webhooks | No | No |
| SDKs | None | None |
| Multi-tenant | No | No |
| Tagline | Modern local SMTP catcher. | Classic local SMTP catcher (unmaintained since 2020). |
| Free tier | Free, MIT-licensed | Free, MIT-licensed |
| Starts at | Free | Free |
| Pricing model | self-hosted | self-hosted |
| API | Yes | Yes |
| SMTP | Yes | Yes |
| Templates | none | none |
| React Email | No | No |
| Inbound | No | No |
| Idempotency | No | No |
| Dedicated IP | No | No |
| Deliverability | Not applicable; capture-only. | Not applicable; capture-only. |
| DX score | 9/10 | 5/10 |
| Best for | Replacing MailHog in any local or CI email-capture setup. | Legacy projects already wired to it. |
Mailpit
pros
- ›Single Go binary or small Docker image with no runtime dependencies
- ›Reuses MailHog's 1025 and 8025 ports, so most existing configs work unchanged
- ›Views for rendered HTML, plain text, raw source, headers, and attachments
- ›Built-in HTML-compatibility check, link check, and spam-score view
- ›REST API and real-time inbox updates for automated tests
cons
- ›Local development and staging only, not a production sender
- ›No hosted or shared team-inbox mode
MailHog
pros
- ›Familiar from years of tutorials and boilerplates
- ›Single Go binary with a Docker image and a chaos-testing mode
cons
- ›No meaningful releases since 2020
- ›HTML and modern CSS rendering trails current email clients
- ›Open issues and pull requests are effectively unattended