Real-Device Checks

Our previews simulate 21 clients. A real-device check goes one step further: it sends your email to real email clients, takes a screenshot in each, and puts those screenshots next to the simulation, so you can compare the two.

Classic Outlook is where this matters most. It lays your email out with Microsoft Word, which no browser can fully imitate. We rebuilt our Classic Outlook simulation from real screenshots and it now matches real Outlook on 177 of 179 layout test cases, but a real screenshot is the final word before you send.

Run a check

1. Open a preview in the dashboard, or a captured message in the Sandbox.
2. Click Real devices.
3. Confirm. The button shows progress (Capturing 18/43) while screenshots come in; you can close the window, the run continues and is saved with the email.

Most clients finish in one to three minutes. A run is complete when the slowest client is. After ten minutes a run finishes with whatever has arrived, and any client still missing is marked as such. If nothing arrived at all, the run fails and your check is given back.

Read the results

• In the preview. When a run has a screenshot for the client you are viewing, the Simulated badge in the canvas becomes a Simulated / Real switch. Choose Real to see the screenshot in the same frame. Your choice stays as you move between clients. In dark mode, the dark capture is used when there is one.
• In the gallery. Click Real devices again to see every screenshot, grouped by family (Classic Outlook, other Outlook, Apple, phones and tablets, webmail, other desktop). Filter by family or by light and dark captures. Open one to see it large, switch between Whole window and Email only, step through clients with the arrow keys, or click Compare with simulation to jump back to the canvas.

Clients covered

A full check covers 40+ real clients, including:

• Outlook 2003, 2007, 2010, 2013, 2016 and 2019 on Windows
• Outlook for Mac, light and dark
• Apple Mail, light and dark
• iPhone (several models) and iPad, in Apple Mail
• Outlook.com and Office 365, light and dark
• Yahoo, AOL, iCloud and several regional webmail clients
• Thunderbird, Windows 10 Mail, eM Client and Postbox

Not covered: the Gmail app on iPhone, the new Outlook for Windows, Samsung Mail, and iPhones newer than the 13.

Plans

• Free: one real-device check per account, on the 12 clients most emails are judged on (Outlook 2016 and 2019, Office 365 light and dark, Outlook.com light and dark, Apple Mail light and dark, Outlook for Mac, Windows 10 Mail, iPhone 13 and Yahoo). It unlocks once your email address is verified and you have run one preview.
• More checks, on every client: coming as a paid add-on.

Running the same email again within 24 hours returns the saved run and does not use a check; Check again uses one only if the email changed. Screenshots are kept for 90 days.

What to expect in a screenshot

• Desktop screenshots are a window, not the whole page. Windows clients and webmail stop at about 3,900px tall, Apple Mail and Outlook for Mac at about 2,540px. A long email is cut off at the bottom; phone screenshots are full length.
• Grey bars in desktop and iPhone screenshots hide the sender and recipient of the test inbox used to take them. Webmail screenshots start at your email instead.
• Fine lines can blur. Screenshots are compressed images; do not judge a 1px border from them.
• A client can occasionally be missing from a run. That is the capture, not your email.

How far to trust each client

Privacy

Your email's HTML is sent to our rendering partner to take the screenshots. We copy the screenshots to our own storage and delete the email and screenshots from the partner as soon as the run ends.