Inbox Pirates: email testing across clients, $1.3K a month, self-reported in 2022

Inbox Pirates helps teams preview and test emails across screen sizes, clients, operating systems, and devices. Its $1.3K a month was founder-reported on the Indie Hackers product page (not independently verified), as of October 2022.

What it actually sells

Inbox Pirates sells email preview and testing software for optimizing emails across devices and clients. The site says: “Preview emails on different screen sizes, email clients, operating systems & devices.” It also previews how an email looks when stacked against 100 other messages.

How it charges

The site offers a free forever plan. It says the starter plan is recommended for agencies needing better support. The page also lists a free-account path alongside a book-a-demo option, while the site excerpt says: “Inboxpirates has a free forever plan.”

Where customers come from

The site identifies email marketers, sales teams, agencies, and businesses sending email campaigns as the audience. It says: “Efficient sales & marketing teams ♥ us, so would yours.” The site also offers a live demo without signup, Chrome extension installation guidance, a demo video, book-a-demo, and a free-account path.

What stands out

Inbox Pirates tests emails against a realistic inbox containing other messages. It checks emails against an updated list of spam words and tests deliverability problems that may hurt email delivery. The product works through a Chrome extension integrated with email service providers, and the site says: “Inboxpirates works right out of the browser and works with your favorite email tools.”

From the official site

Inboxpirates has a free forever plan.

Preview emails on different screen sizes, email clients, operating systems & devices.

Inboxpirates works right out of the browser and works with your favorite email tools.

Excerpts from the official website, fetched October 1, 2026.

Where it sits in the data

Inbox Pirates's $1.3K a month is higher than 45% of the 6,604 projects with founder-reported monthly revenue in our dataset; the median across them is $2K. Snapshot: 2026-09-30. The dataset only covers founders who chose to publish their numbers, so it leans toward businesses that work; use it for scale, not as an average.

Currency

All figures are in US dollars as published. A rough yuan or euro conversion is not applied here because prices, taxes and acquisition costs differ by country.

Could you build something like this?

In my view, demand would come from email marketers, sales teams, agencies, and businesses sending email campaigns that need to review messages across clients and devices. Distribution could come from a live demo without signup, Chrome extension installation guidance, a demo video, book-a-demo, and a free-account path.

In my view, the hard part is maintaining previews across email clients, operating systems, and devices while keeping deliverability and spam-word checks current. The product also needs integration support and must explain the value of previews to buyers who are deciding whether to read an email.

Verdict: Needs real work.

One thing to take from it

The product shape is focused on a recurring email workflow: previewing a message, checking it against other messages, checking spam words, and checking deliverability. The site claims it serves more than 250 teams worldwide and says its tool can increase email opens by 20%.

Sources

Inbox Pirates official website, fetched October 1, 2026
Inbox Pirates pricing page, fetched October 1, 2026
Inbox Pirates about page, fetched October 1, 2026
Indie Hackers product page: revenue founder-reported on the Indie Hackers product page (not independently verified), as of October 2022

Revenue, team and start-cost figures are what the founder reported at the interview date, not current figures and not a prediction of what you will earn. Product and pricing facts come from the business's own website as checked on 30 September 2026. Method & sources · Disclosure