Free tool · Email spam test
Free email spam test
Paste your email to check it before you send: bounce risk, links that won’t work, readability and Gmail’s ~102KB clip. Then check your sending domain’s SPF, DKIM and DMARC, which Gmail and Yahoo require from bulk senders. Free, no signup.
What it checks
What this spam test checks, and what it doesn’t
Spam tests come in two kinds. Seed-list tests send your email to a set of test inboxes and report where it landed. Content and setup checks look at the email and your domain before you send. This is the second kind.
What it checks
- Your sending domain’s SPF, DKIM and DMARC, under Check a domain. Missing authentication is one of the most common reasons bulk mail is filtered or rejected.
- Bounce risk, rated low, elevated or high.
- Links with no destination, or one that isn’t a usable web address.
- Email weight, and whether Gmail will clip it.
What it doesn’t
It doesn’t give a spam score, test your sending IP’s reputation or check blocklists. It can’t see how your readers engage either, and that’s one of the biggest things Gmail and Outlook weigh. For that, look at opens and complaints by mailbox provider, and keep your list clean.
Why newsletters land in spam
- Missing or broken SPF, DKIM or DMARC.
- Sending to people who stopped opening, or to addresses that bounce.
- Complaints from readers who didn’t expect the email or couldn’t find the unsubscribe link.
- A sudden jump in volume from a new domain or platform.
In Letterhead, these checks run while you write.
Every issue gets a content check before it goes out: bounce risk, links that won’t work, what an AI inbox will read, readability, and email weight with what’s making it heavy. Letterhead also strips redundant styling from what it sends, so your newsletter goes out lighter than you wrote it.
| The old way | In Letterhead |
|---|---|
| Find out Gmail clipped you when a reader asks where the unsubscribe link went. | Email Weight shows how heavy every issue is, and what’s making it heavy, before you send. |
| Click every link by hand the morning of the send. | Links with no working destination are flagged in the editor before you send. |
| Paste the HTML into another tool to slim it down. | Letterhead strips redundant styling from what it sends, so it goes out lighter than you wrote it. |
FAQ
Questions about spam tests
Does this give my email a spam score?
No. It checks your content and your domain’s setup before you send. It doesn’t send your email to seed inboxes or score it.
Why is my newsletter going to spam?
The most common reasons are missing authentication (SPF, DKIM, DMARC), sending to unengaged or invalid addresses, and reader complaints. Check your domain here, then look at engagement by mailbox provider.
Will fixing SPF, DKIM and DMARC get me out of spam?
It’s required, but it isn’t always enough. Gmail and Yahoo also weigh complaints and engagement.
Do you keep the domain or email I check?
No. We don’t store what you paste or the domain you look up.
The Letterhead Brief
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The Brief lands once a week. Want these checks running on your own newsletter? Book a test drive →