What’s the truth about “sender score” vs “filter reputation”?
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You check your Sender Score, see a 91, and feel pretty good. Then your emails stop reaching Gmail inboxes. What happened?
This is the gap between Sender Score and filter reputation, and it trips up a lot of senders.
Sender Score is a metric from Validity (formerly Return Path). It rates your sending behavior on a 0-to-100 scale based on data Validity collects through its own network of partner inboxes and monitoring points. It's a third-party view of your reputation, not an internal one.
Filter reputation is what each mailbox provider actually uses to decide where your email goes. Gmail, Outlook, and Yahoo Mail each maintain their own internal scoring. It's built from signals they see directly: how their users interact with your mail, your complaint rates, your authentication setup, your sending patterns, and more. None of them publish it. You don't get a number.
These two things can point in the same direction, but they don't have to. A healthy Sender Score suggests your sending behavior is generally in good shape. It doesn't mean Gmail agrees. Gmail's Postmaster Tools gives you the closest window into your Gmail-specific reputation, showing domain reputation and IP reputation as bands (Bad, Low, Medium, High) rather than a tidy score.
The honest answer is that Sender Score is worth watching as a directional signal. If it drops, something changed. But the only real measure of your reputation with any specific provider is how your mail actually performs there: delivery rate, spam folder rate, engagement. Real data from a real inbox beats any third-party proxy.
If you're trying to debug a deliverability problem, start with Postmaster Tools for Gmail, and look at your actual bounce and placement data before assuming the Sender Score tells the whole story. Not sure where to start? Our SOS hotline is free and we'll help you figure out what's actually going on.
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