Why are your Kit emails going to spam?

Broadcast opens dropped off a cliff, or a reader said you're in their junk folder? Here are the five real reasons — and a 30-second test that shows exactly where your next broadcast lands.

Forward a test email here
slithering-sloth-5577@in.mailtester.ai

The honest diagnosis

Five things decide where your Kit broadcast lands. Not luck.

Most advice is a generic checklist that ends in a list-cleaning upsell. Here's the honest version: five signals decide whether a broadcast reaches Primary, Promotions or spam — and you can check every one on the exact email you're about to send.

Authentication

Your sending domain isn't verified — so nothing proves it's you.

The most common Kit-specific miss: broadcasts going out without a verified custom sending domain. Since Gmail and Yahoo tightened bulk-sender rules, mail whose DKIM doesn't align with the sender's own domain starts every delivery at a disadvantage. Verify the domain in Kit, then confirm SPF, DKIM and DMARC actually pass — a half-finished setup fails silently.

List quality

Cold segments and old imports poison the whole send.

That lead-magnet list from 2023, the import from your previous platform, the tag you never mail — every cold slice you include drags open rates down and complaint rates up on the entire broadcast. Mailbox providers score the send as a whole. Mail your engaged core consistently; win the rest back in small, separate batches.

Content

A broadcast that reads like a promotion gets filed like one.

Five tracked links, a countdown, a discount code — individually fine, together they read as marketing, and Gmail files marketing under Promotions. That's survivable. What tips into spam is promo-heavy content ON TOP of weak authentication or a tired list. Fix those first; polish copy second.

Cadence

Launch-week bursts look like a different sender.

Quiet for a month, then six emails in launch week: to a mailbox provider that's a behavior change worth throttling. Keep a steady baseline rhythm between launches, and stagger launch sequences so the volume curve looks like a sender they know — not a burst from a stranger.

Reputation

Your domain's history compounds, send after send.

Complaints, dead addresses, spam-trap hits — each one nudges a per-domain score that follows you for weeks. It's why one bad blast hurts long after it. The recovery is boring and works: prune never-openers, keep cadence steady, and check each broadcast before it ships.

Spam vs Promotions

Most of the time it's not spam — it's Promotions.

Check which tab you're actually in before treating this as a crisis. Promotions is a real inbox with real readers; a creator newsletter can do fine there. Actual spam is a different problem with a different fix. The test below tells you which one you have — on your real broadcast, not a template.

Stop guessing

See where YOUR Kit broadcast actually lands.

You can second-guess subject lines all afternoon and still be guessing. Or forward the broadcast and see it: we open your real email in real Gmail, Outlook and Yahoo accounts and show the split — Primary, Promotions, Spam — plus the three fixes worth doing first, in plain English. About 30 seconds, free.

Address validity

Does this address exist?

You upload a CSV of subscribers. The tool tells you which addresses bounce. Great for cleaning a stale list before a re-engagement send.

Inbox placement

Will Gmail actually show it?

You forward one email — newsletter, launch, client note — to a one-time mailbox. We open it in real Gmail, real Outlook, and Yahoo and tell you which tab it landed in, plus what to rewrite before you send it to your list.

FAQ

Kit (ConvertKit) Emails Going to Spam? Test It Free

Why are my Kit (ConvertKit) emails going to spam? Five signals decide it: authentication (an unverified sending domain is the most common Kit-specific miss), list quality (old imports, cold segments), content (a broadcast that reads like a promotion), cadence, and sender reputation. Forward the exact broadcast to a test mailbox and the report shows which of the five is biting.

Do I need a verified custom domain in Kit? Yes, if you're serious about placement. Without a verified sending domain your broadcasts authenticate against Kit's shared infrastructure.

Why did my re-engagement broadcast make things worse? Blasting the coldest slice of your list concentrates the worst signals into one send: no opens, high deletes, a few spam complaints. That single broadcast can drag your sender score for weeks. Re-engage in small batches, and cut subscribers who don't respond rather than mailing them again.

Plain emails still land in Promotions — why? Gmail tabs weigh more than looks: bulk headers, link count, your sending history and how YOUR readers engage. A plain-text broadcast with five tracked links and a discount code still reads as a promotion. Promotions also isn't spam.