How to tell if content or reputation is the problem?

Your emails are hitting spam and you want to know why. Is it something in your content tripping filters? Or is your sending reputation already damaged? These two problems look identical from the outside but need completely different fixes, so it's worth running a quick test to tell them apart.

The idea is simple: hold one variable steady while you change the other.

Test 1: Isolate your reputation

Send a stripped-down email from your normal sending domain. Plain text, no images, no links, a single short sentence like "This is a test email from [your brand]." Send it to a handful of your own seed addresses across Gmail, Outlook, and Yahoo. Wait 15-30 minutes and check placement.

So if If that plain-text email still lands in spam, your reputation is the problem. The content couldn't be cleaner, so the filter is reacting to your sending domain or IP, not your message.

Test 2: Isolate your content

Now flip it. Take your actual campaign, the one going to spam, and send it from a completely fresh domain with no sending history. You can spin up a test domain or use a service like Mailtrap to send from a clean environment. Send to the same seed addresses and check placement.

If the same content lands in the inbox from the fresh domain, your content is probably fine and your reputation is the culprit. If it still goes to spam from the clean domain, something in the content itself is triggering filters.

What to look at while you wait

You don't have to run blind. Gmail Postmaster Tools gives you a direct read on your domain reputation. If it's showing "Low" or "Bad", that's your answer before you even finish testing. Clean reputation scores with spam placement almost always point back to content.

It's also worth asking yourself one diagnostic question before testing anything: did the spam placement start right after a content change (new template, new link, new image-heavy layout), or did it start after a sending event like a big blast to an old list? That timing tells you a lot. Content problems tend to appear suddenly when something changes. Reputation problems often creep in gradually after volume spikes, high complaints, or bounce surges.

Reading your results

• Bland content from your domain goes to spam. Reputation problem. Focus on re-engagement, list hygiene, and complaint reduction.
• Real content from a fresh domain goes to spam. Content problem. Look for spammy phrases, excessive links, broken HTML, or image-to-text ratio issues.
• Both tests go to spam. You've got both problems. Start with reputation, then address content once your domain health improves.
• Both land in the inbox. The issue might be specific to one mailbox provider. Check which ISP is spamming you and test against that one specifically.

And If you're not sure where to start, our SOS hotline is free and we can walk through your setup with you.