A trust score inboxes assign to your sending domain and IP, built from how you’ve sent email over time.
What Is Email Sender Reputation?
Sender reputation is how much a mailbox provider trusts email coming from your domain, based on your sending history. It works a lot like a credit score, built gradually, and it directly influences whether your next campaign lands in the inbox or gets filtered.
Why Sender Reputation Matters
Every email marketing send draws on this reputation before a single subscriber sees anything. A strong reputation means inboxes give your emails the benefit of the doubt. A weak one means even a well-written campaign can get filtered before it’s ever opened.
For ecommerce stores, this compounds. One reckless send, blasting an old, unclean list, can damage the reputation your abandoned cart and post-purchase flows depend on for weeks afterward.
What Affects Sender Reputation
– Complaint rate: how often people mark your email as spam
– Bounce rate: how many emails go to invalid addresses
– Engagement: opens, clicks, and replies over time
– Sending consistency: steady patterns versus sudden spikes
– Blacklist status: whether your domain or IP has been flagged
– Spam trap hits: sending to old, unused, or fake addresses used to catch bad senders
How to Check Your Sender Reputation
1. Use Google Postmaster Tools to see domain and IP reputation from Gmail’s perspective
2. Run a seed list test through a tool like GlockApps to see real inbox placement
3. Check your bounce and complaint rate trends inside your email platform’s dashboard
4. Run a blacklist check on your sending domain and IP periodically
How Adflipr Helps
Adflipr tracks bounce and complaint trends automatically inside your dashboard, so reputation issues show up before they turn into a deliverability problem. Combined with automatic hard bounce suppression, this keeps the signals that build reputation clean without extra manual work.
Best Practices
– Check your reputation monthly, not just after a campaign underperforms
– Keep bounce rate under 2% and complaint rate under 0.1%
– Warm up new domains gradually instead of sending full volume on day one
– Segment sends so inactive contacts don’t drag down engagement signals for your whole list
Common Mistakes
– Only checking reputation after deliverability already drops
– Sending to a purchased or scraped list, which almost always includes spam traps
– Ignoring a slow decline in engagement until it becomes a real problem
– Assuming one good campaign undoes months of reputation damage
Frequently Asked Questions
Mailbox providers weigh complaint rate, bounce rate, engagement, sending consistency, and blacklist status together. There’s no single public formula, but these signals consistently show up across every major provider’s guidance.
Google Postmaster Tools is free and shows domain and IP reputation directly from Gmail. Combine it with a seed list test or a free blacklist checker for a fuller picture across providers.
A sudden spike in complaints or bounces, usually from sending to a purchased list or an old, unclean one. One bad send to a large enough list can undo months of steady, careful sending.
Usually two to six weeks of clean, consistent sending, depending on how serious the damage was. There’s no instant fix, since mailbox providers need to observe improved behavior over time before trust rebuilds.
