What’s the best order to check (authentication, engagement, content, domain)?
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Your emails are landing in spam and you want to fix it fast. The temptation is to jump straight to content, tweak a subject line, and hope for the best. That rarely works. The reason the order matters is that each layer builds on the one before it. Fix the wrong thing first and you're patching a roof while the foundation is cracked.
Here's the order that actually makes sense, and why.
Step 1: Authentication (SPF, DKIM, DMARC)
Start here. If your SPF record is broken, your DKIM signature is missing, or your DMARC policy is misconfigured, mailbox providers have no way to confirm your email is legitimate. They won't reward good content from a sender they can't verify. Authentication issues are also the easiest to confirm and fix. You can check them in minutes with a free tool.
Run your SPF and DKIM through our free SPF checker and DKIM lookup right now. If something's broken here, fix it before touching anything else.
Step 2: Domain and IP reputation
Once authentication is clean, check whether your sending domain or IP address is on a blocklist. A single blocklist listing can tank delivery across entire provider networks. It doesn't matter how engaging your content is if the message is being rejected before it even reaches a spam filter.
Our blocklist checker scans the major lists in seconds. If you find a listing, that's your culprit. Focus on getting delisted before moving on.
Step 3: Engagement signals
And this is where most senders underestimate the problem. Gmail and other modern mailbox providers weight engagement heavily. If you've been sending to a large chunk of unengaged subscribers, opens and clicks have been dropping, and complaints have been ticking up, that's a reputation signal they're acting on. No amount of subject line polish fixes a sender whose list hasn't been cleaned in two years.
Look at your recent open rates, click rates, and complaint rates by segment. If your engaged subscribers are getting good placement and your unengaged ones aren't, the issue isn't content. It's list hygiene and sender reputation. Suppressing or re-engaging cold subscribers before your next send can make a noticeable difference quickly.
Step 4: Content
Content is last for a reason. Spam filters in 2024 are much more sophisticated than keyword matching, but certain patterns still trigger them. Excessive use of images with minimal text, spammy phrases, broken HTML, misleading subject lines, and missing plain-text versions can all push you toward the spam folder. If your authentication is clean, your domain reputation is healthy, and your engagement is solid, but you're still seeing placement issues, now is the time to audit your content carefully.
Run your subject lines through our subject line tester and check your email source with the source analyzer to spot anything unusual.
Why this order works
Authentication is the foundation. Reputation is built on that foundation over time. Engagement shapes reputation on an ongoing basis. Content is what the filter evaluates after it's already decided whether to trust you. Skipping ahead to content when authentication is broken is a waste of time. And fixing content when the real issue is a blocklist listing won't move the needle at all.
Work through the layers in order. You'll find the real problem faster, and you won't spend three days rewriting email copy when a five-minute DNS fix was all you needed.
Not sure where to start? Our SOS hotline is free. We'll help you figure out which layer is the culprit without the guesswork.
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