By Folderly · Pre-send checkpoint

Check the email before the inbox does.

Paste or upload HTML and get an instant readiness verdict: send, fix, or investigate — with the top fixes, affected inboxes, and a labeled content deliverability risk in one pass.

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Built on the engine behind Folderly · Nothing stored, nothing trained on · Free while in beta

Readiness

--/100Awaiting HTMLephemeral · no training · fidelity labeled

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HTML message

Add your sending domain to check SPF, DKIM and DMARC and upgrade the verdict beyond content-only.

<!doctype html><html><head><style>@media(max-width:600px){.col{width:100%}}</style></head>
<body style="margin:0;font-family:Helvetica,Arial,sans-serif;background:#eef;">
<div style="position:relative;height:120px;background:#0D9488;">
<div style="position:absolute;top:40px;left:40px;color:#fff;font-size:26px;font-weight:bold;">Launch day is here</div></div>
<div style="display:flex;gap:16px;padding:24px;">
<div class="col" style="flex:1;background:#fff;border-radius:16px;padding:20px;box-shadow:0 4px 12px rgba(0,0,0,.1);">
<h3>Feature one</h3><p style="color:#555;">A grid layout that Outlook will not respect.</p></div>
<div class="col" style="flex:1;background:#fff;border-radius:16px;padding:20px;box-shadow:0 4px 12px rgba(0,0,0,.1);">
<h3>Feature two</h3><p style="color:#555;">Background images get dropped in Outlook desktop.</p></div></div>
<div style="text-align:center;padding:20px;">
<a href="#" style="background:linear-gradient(90deg,#0D9488,#2B6FEE);color:#fff;padding:14px 30px;border-radius:30px;text-decoration:none;font-weight:bold;">GET STARTED NOW!!!</a></div>
</body></html>

Testing against 8 of 8 inbox clients ·

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How accurate are these previews?

Every preview carries its fidelity label: engine-accurate runs a real rendering engine, engine-approximated applies known client quirks, rule-simulated is a documented rule pass. Nothing is ever passed off as a real client when it isn't.

What does it cost?

Free while in beta — no card, nothing stored, repeat checks never bill twice. Beta users get first access to pricing before it goes live.