How to check if your emails are landing in spam before you launch a campaign

spam_detective · 2026-03-10 · 1,980 views

Do not launch a cold email campaign without testing deliverability first. I see people skip this step constantly and then wonder why their reply rate is 0.3%. Here are 6 steps to check if your emails are hitting the inbox or going straight to spam. Takes 15 minutes. Saves you from burning inboxes and domains.

Step 1: Send test emails to your personal Gmail and Outlook accounts.

This is the simplest test and the one most people skip. Create a personal Gmail account and a personal Outlook account if you don't already have them. Send a test email from each of your cold email inboxes to both accounts. Use your actual cold email copy, not a test message. Check where the email lands. Primary inbox? Promotions tab? Spam folder? If any of your accounts are landing in spam on this basic test, do not start a campaign from those accounts. Something is wrong with the warmup, DNS, or the account's sender reputation. Fix it before you send a single cold email.

Step 2: Check if they land in primary, promotions, or spam.

Primary inbox is what you want. Promotions tab is a yellow flag. It means Gmail thinks your email looks like marketing content. Usually caused by HTML formatting, tracking pixels, or too many links. Rewrite your email in plain text, remove tracking pixels, and remove links from the first email. Spam means a red flag. DNS misconfiguration, burned sender reputation, or content that triggers spam filters. Check Steps 3 through 6 to diagnose the specific problem.

Step 3: Run your copy through PuzzleInbox spam word checker.

Go to the PuzzleInbox spam checker and paste your email copy. It checks for spam trigger words (free, guarantee, limited time, exclusive, act now, click here), excessive capitalization, spammy formatting patterns, and missing personalization variables. Remove every flagged word or phrase. Rewrite around them. A single spam trigger word won't tank your deliverability, but stacking 3 or 4 in one email will push you closer to the spam threshold.

Step 4: Use mail-tester.com for a quick score.

Go to mail-tester.com. It gives you a unique email address. Send your cold email to that address from one of your inboxes. Mail-tester scores your email on a 10-point scale and tells you exactly what passed and what failed. Check SPF, DKIM, and DMARC authentication. Check the content score. Check if your IP or domain is on any blacklists. A score of 8 or above means you're in good shape. 6 to 7 means fix the flagged issues before launching. Below 6 means stop and diagnose before sending anything.

Step 5: For serious testing, use GlockApps seed list testing.

GlockApps ($79/month) sends your test email to real seed mailboxes at Gmail, Outlook, Yahoo, AOL, and other providers. It tells you the exact inbox placement percentage. 85%+ inbox placement means you're safe to launch. 70 to 84% means something is off and you should investigate before scaling. Below 70% means your campaign will underperform significantly. GlockApps is overkill if you have 5 inboxes. It is mandatory if you manage 20+ inboxes or run an agency.

Step 6: Check your DNS with MXToolbox.

Go to MXToolbox.com. Run an email health check on your sending domain. It checks SPF, DKIM, DMARC, MX records, blacklist status, and server configuration. All green means you're good. Any red flags mean something in your DNS needs fixing. Common issues: missing DMARC record (easy fix, add a TXT record), multiple SPF records (combine them into one), DKIM not signing (enable DKIM signing in your email admin panel). If you bought inboxes from PuzzleInbox, all of this should already be passing. But verify anyway. Trust but verify.

Don't skip this before any new campaign. Every new campaign, every new inbox, every new domain. Run these checks. The 15 minutes you spend testing saves you from days of wasted sending, burned accounts, and zero replies. Cold email deliverability is fragile. A small DNS issue or a few spam trigger words can be the difference between a 4% reply rate and a 0% reply rate. Test first. Send second.