What is Sender Reputation?
Sender reputation is a score assigned by inbox providers based on your sending history, determining whether your emails reach the inbox, spam folder, or are rejected entirely.
Sender reputation is a dynamic score that inbox providers (Gmail, Microsoft, Yahoo) assign to your sending domain and IP addresses based on your email behavior. It determines where your emails land: inbox, spam, or rejected.
Reputation is built over time from multiple signals: bounce rates, spam complaint rates, engagement (opens, clicks), sending volume consistency, authentication compliance, and spam trap hits. Each inbox provider calculates reputation independently, so you may have good reputation with Gmail but poor reputation with Microsoft.
For multi-tenant platforms, reputation management is especially complex. Each tenant's sending behavior affects their domain reputation. If tenants share IPs, poor senders can drag down everyone's reputation. Monitoring per-tenant sending metrics and managing sending limits are important for maintaining platform-wide deliverability.
Why Sender Reputation Matters
Sender reputation is the single most important factor in email deliverability. A poor reputation means your emails go to spam regardless of content quality or authentication. For platforms, monitoring per-tenant sending metrics helps identify problem senders before they affect platform-wide deliverability.
Frequently Asked Questions
What is sender reputation?
Sender reputation is a score inbox providers assign based on your sending history—bounce rates, spam complaints, engagement, and authentication. It determines whether your emails reach the inbox, go to spam, or get rejected.
How do I check my sender reputation?
Google Postmaster Tools shows your domain reputation with Gmail. Microsoft SNDS provides Outlook reputation data. Third-party tools like Sender Score provide a general reputation estimate. Ark provides per-tenant reputation monitoring in the dashboard.
How long does it take to build sender reputation?
Building a positive reputation typically takes 4-8 weeks of consistent, low-bounce, low-complaint sending. This is why IP warmup is important for new sending infrastructure. Damaging reputation happens much faster—a single bad send can take weeks to recover from.
Related Terms
Email Deliverability
Email deliverability is the ability to successfully deliver emails to recipients' inboxes rather tha...
IP Warmup
IP warmup is the process of gradually increasing email volume from a new IP address to build sender ...
Tenant Isolation
Tenant isolation in email ensures that each customer's sending data — suppression lists, analytics, ...
Bounce Rate
Email bounce rate is the percentage of emails that couldn't be delivered to recipients, categorized ...
Feedback Loop
A feedback loop (FBL) is a service provided by inbox providers that notifies you when recipients mar...
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