Glossary
Sender reputation
Sender reputation is how much mailbox providers trust mail from your domain and IP addresses, based on recipient complaints, engagement, bounces, spam trap hits and authentication. It decides whether your email lands in the inbox, the spam folder or gets rejected.
What Is Sender Reputation?
In short There is no single score.
Gmail, Outlook and Yahoo each keep their own view of your domain, your sending IPs and sometimes individual mailboxes, and none of them publishes the formula. What they do publish: authenticate with SPF, DKIM and DMARC, keep spam complaints low and make unsubscribing easy. Google and Yahoo both set a spam rate limit of 0.3%.
Domain reputation follows you. IP reputation mostly does not when you send from Google Workspace or Microsoft 365. That is why cold email teams send from secondary domains: if a campaign damages one domain, the main domain's customer and team mail keeps working.
Sender Reputation Example
Example: a team sends 1,500 cold emails a day across 10 domains. One domain gets an old list, its bounce rate hits 6% and replies stop. The team pauses that domain, keeps the other 9 running and re-verifies the list before that domain sends again.
Sender Reputation in Practice
Reputation builds slowly and drops fast. Google says a bulk sender whose spam rate goes above 0.3% loses eligibility for mitigation until the rate stays below 0.3% for 7 consecutive days. Recovery means cutting volume and sending only to engaged recipients until the numbers come back.
FAQ
What is sender reputation?
The trust mailbox providers place in mail from your domain and IPs, built from complaints, engagement, bounces and authentication. It decides inbox, spam folder or rejection.
How do I check my sender reputation?
No public score covers every provider. Use Google Postmaster Tools for Gmail, Microsoft SNDS for Outlook.com if you own your sending IPs, and Spamhaus's checker for blocklists. Watch your own bounce, complaint and reply rates per domain too.
What hurts sender reputation the most?
Spam complaints, high bounce rates from bad lists, spam trap hits and sudden volume spikes. Missing authentication makes all of them worse.
How do you improve sender reputation?
Authenticate with SPF, DKIM and DMARC, verify lists before sending, keep daily volume steady, send fewer emails to more relevant people and remove anyone who bounces or asks to stop.
Do This in Ken
Do This in Ken
Delivery checks authentication on every sending domain and enrolls new Google Workspace mailboxes in warmup automatically, two parts of sender reputation you control before the first campaign.
- Module
- Delivery
- Open in Ken
- /features
The new Ken opens to the waiting list in batches.
Related
- GTM Glossary
Every GTM term, grouped by topic.
- IP reputation
- Email warmup
- Email bounce rate
- Google Postmaster Tools
- DMARC
- Spintax
- Ken
Sources
| Source | Checked |
|---|---|
| Google: Email sender guidelines | |
| Gmail Help: Email sender guidelines FAQ | |
| Yahoo Sender Hub: Sender best practices |
Changelog
- Page published.