Can a clean IP still be filtered?
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Got a clean IP? Great. But don't stop there. IP reputation is just one piece of what filters look at, and it's not even the most important one anymore.
Think about it this way. You could be sending from a perfectly clean IP and still land in spam because your domain has a bad reputation. Filters look at your domain's history separately from your IP's history. If the domain attached to your "from" address has racked up complaints or bounces in the past, that follows you around no matter which IP you use.
Then there's content. A suspicious link, a subject line that reads like an ad for miracle cures, or broken HTML can trigger filtering on its own. None of that has anything to do with your IP.
Authentication failures are another common culprit. Missing or misconfigured SPF, DKIM, or DMARC tells filters they can't verify you actually sent the message. A clean IP doesn't fix that.
And then there's engagement. If your recipients aren't opening, clicking, or moving your emails out of spam, filters notice. They build a picture of how people respond to mail from your domain and your address, not just your IP. Low engagement over time will drag you down even if everything else looks fine.
The short answer is that filters weigh all of these signals together. IP reputation gets your foot in the door, but your domain history, content quality, authentication setup, and subscriber engagement all have to hold up too. (Plenty of senders fix their IP and wonder why they're still filtered. Now you know why.)
If you're not sure where the problem actually is, our free Email Header Analyzer can help you trace what filters are actually seeing. Or if things are broken right now, the SOS hotline is free.
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