Perenmail vs MailHog
Both tools help developers work on the email their applications produce, but they sit on opposite ends of the pipe. MailHog is a popular free, open-source, self-hosted tool: you run it locally or in your cluster, and its fake SMTP server captures the outbound mail your app tries to send into a local web UI, so it never reaches real recipients. Perenmail is a hosted service — nothing to run or maintain — that receives real inbound mail on real domains into persistent, private inboxes you inspect by hand.
Two different jobs, compared
A dimension-by-dimension look at where each tool fits. Perenmail is a hosted service oriented around real inbound delivery and persistence; MailHog is a self-hosted fake SMTP server that traps outbound test sends locally.
| Dimension | Perenmail | MailHog |
|---|---|---|
| Hosting model | Hosted service — nothing to run or maintain. Sign in and start inspecting mail immediately. | Self-hosted — you run the binary or container locally or in your cluster and keep it running. |
| Mail direction | Inbound — real messages are delivered to a real address you own and appear as they arrive. | Outbound — a fake SMTP server captures what your app tries to send so it never leaves the box. |
| Real domain delivery | Yes — a private address on a real domain that accepts genuine inbound mail over SMTP. | No — MailHog holds captured sends in a local web UI; it does not receive real mail on public domains. |
| Persistence | Persistent by default. Inboxes never expire on their own; you keep them until you archive or delete. | Typically ephemeral to the running instance — captured mail is tied to that process and its storage. |
| Setup & maintenance | None — no infrastructure, upgrades, or process to babysit. It is always available. | You install, configure SMTP pointing, and keep the instance patched and running yourself. |
| OTP / link capture | One-tap: verification codes and every link are extracted so you can copy a code or open a link in one click. | Renders captured messages in its web UI; extraction of codes or links is left to you by hand. |
| Raw headers & auth results | Full RFC822 source with synthesized SPF, DKIM and DMARC results, to debug your own outbound email. | Shows the raw captured message and headers; it is not delivered, so there are no real auth results. |
| Best for | Developers who want a real, persistent address that accepts genuine inbound mail and see exactly what arrives. | Local, offline development where you want to trap outbound mail on your own machine with zero dependencies. |
See what actually arrives
Because the mail is really delivered to an address you own — with no server to stand up — you inspect the genuine message that arrives, and it stays put for as long as you need it.
Real inbound delivery
Point a live signup, OTP, or password-reset flow at a real address on a real domain and inspect the exact message that arrives — not a local capture of what your app tried to send before it left the box.
Nothing to run
There is no binary to install, no container to keep running, and no instance to patch. The service is hosted and always available — you sign in and the mail is there.
Persistent inboxes
Inboxes never expire on their own, and they are not tied to a running process. Delayed and cron-scheduled email is still waiting when it finally lands, hours or days later — not lost when a container restarts.
One-tap OTP capture
Verification codes and every link in a message are extracted for you. Copy the code or open the link in a single click while you work through a flow.
Raw headers & auth
The full RFC822 view with synthesized SPF, DKIM and DMARC results lets you debug your own outbound email down to the header — see how it actually authenticates on arrival.
Testing the mail your staging environment sends? Walk through the hosted approach in QA & staging email, or see how the same setup compares against a hosted sandbox in Perenmail vs Mailtrap.
MailHog is the right tool when you want everything to stay on your own machine. For fully local or offline development — an air-gapped environment, CI that must not reach the network, or a setup where you deliberately want zero external dependencies — running a fake SMTP server locally is exactly what you want: your app points at it, outbound mail is trapped, and nothing ever leaves the box. It is also free and open source, so there is no account, no cost, and no vendor involved. Perenmail deliberately does the opposite: it gives you a hosted address on a real domain, with persistent inboxes to inspect the genuine mail your product delivers — no server for you to stand up or keep running.
Feature details here are accurate as of 2026 and are described in good faith for comparison only. MailHog is a separate open-source project; verify its current behavior on the MailHog project.
Inspect real mail without running a server.
Point a real flow at a real, persistent address and see exactly what arrives — nothing to install. Free forever, no credit card.