Correct. MailSandbox accepts mail on a standard SMTP endpoint and stops it there. Every message is captured, rendered, and stored for review. None of it is ever relayed to the real recipient. Point staging at it and you can send a thousand password resets without a single one landing in an actual inbox.

Captured emails are retained per your plan and can be deleted anytime, manually or on an automatic schedule. Share links are signed with a rotating secret, expire on a window you set, and are revocable in one click. Reviewers only ever reach the single email you shared, never your dashboard or another client.

If it speaks SMTP, it works: Laravel, Rails, Django, Node/Nodemailer, or a raw socket. There is no SDK to install and nothing proprietary to adopt: you change the host, port, and credentials and you are done. Switching back is exactly as easy, so there is no lock-in.

It scales with your plan: the Free plan includes 1 active project and 3 inboxes; paid plans go from 5 active projects on Starter up to 50 on Business, with unlimited inboxes on every paid plan. There is no separate per-client fee, so most agencies just add a project per client and grow into the tier that fits. See the pricing table above for the exact limits on each plan.

Active simply means not archived. Archiving a finished project stops it from capturing new email and immediately drops it off your project count, so you are never paying to keep a wrapped-up client around. Archived projects, and everything inside them, stay fully restorable whenever you need them again.

Anytime. Revoke a single link, regenerate it with a fresh signature, or let it expire on schedule. You also see how many times a link has been opened and when it was last viewed, so you know a review actually happened.

Depends which kind. An anonymous share link needs no account at all: a reviewer clicks it and sees the captured email rendered cleanly in their browser, with none of the MailSandbox interface around it. If you would rather invite a client as a standing collaborator, add them as a client reviewer instead: they log in, but only ever see the specific projects you assign them, with no access to billing, settings, or deletion. Client reviewers are unlimited on every paid plan.

A tester is a lightweight, send-only credential: useful for a developer or QA contractor who needs to push test emails into a project, but not to browse what has been captured. A client reviewer is the opposite: they can open a project and review the emails inside it, but cannot send anything or touch billing, settings, or other projects. Use whichever matches what that person actually needs to do.