# Free email spam test: check your email and domain before you send | Letterhead Source: https://www.tryletterhead.com/tools/email-spam-test.html _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. Check a domain Check an email Sending domain Check domain We check the DKIM selectors Google Workspace, Microsoft 365 and the big email platforms use. If yours isn't one of them, paste the full source of an email you sent, as it arrived (in Gmail: "Show original"), into "Check an email" and we'll read it from there. Know your DKIM selector? DKIM selector It's the s= value in an email's DKIM-Signature header. Your email Paste the full source of a received copy (in Gmail: "Show original") and we'll also find the DKIM selector your domain signs with. Check email _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](../tools/email-list-cleaning.html). ### 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 wayIn LetterheadFind 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. [Book a test drive](../lp/test-drive.html) _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. _More free checks_ ## Check the rest before you send. - [**Preflight**SPF, DKIM, DMARC and a content check, together](../tools/preflight.html) - [**SPF checker**Missing, duplicate and too-open SPF records](../tools/spf-checker.html) - [**DMARC checker**Your policy, and what Gmail, Yahoo and Outlook require](../tools/dmarc-checker.html) - [**DKIM checker**Find your selector and check the key](../tools/dkim-checker.html) - [**Gmail clipping checker**Will Gmail cut your email off at ~102KB?](../tools/gmail-clipping-checker.html) - [**Inbox preview**Your email in real Gmail and Outlook.com inboxes](../tools/inbox-preview.html) - [**Ghost Finder**Is this address real, or a ghost?](../tools/ghost-finder.html) - [**Email list cleaning**Keep bad addresses off your list](../tools/email-list-cleaning.html) - [**Email verifier**Check if an email address is valid](../tools/email-verifier.html) - [**Outlook email preview**See it in a real Outlook.com inbox](../tools/outlook-email-preview.html) [All free tools](../tools/) [See it in Letterhead →](../lp/test-drive.html) × The Letterhead Brief Don't fill this out if you're human: Email address Subscribe One email a week. Unsubscribe anytime. By submitting, you agree to our [Privacy Policy](../legal/privacy-policy.html). [Or book a 15-minute test drive →](../lp/test-drive.html) Not now You're on the list. The Brief lands once a week. Want these checks running on your own newsletter? [Book a test drive →](../lp/test-drive.html)