What sender reputation is
Gmail, Outlook and Yahoo each score your sending domain and IP address, typically on a scale of 0 to 100. The score comes from your sending history, engagement, spam complaints, authentication and list quality. Think of it as a credit score for email: a good one gets you into the inbox, a bad one gets you filtered or blocked.
| Score | Rating | What happens |
|---|---|---|
| 80 to 100 | Excellent | Strong inbox placement. A trusted sender with high engagement and proper authentication. |
| 50 to 79 | Moderate | Mixed signals. Some email reaches spam. |
| Below 50 | Poor | Most email goes to spam or is blocked. |
Providers track two reputations, and both matter:
Domain reputation
Tied to yourdomain.com and follows you wherever you send from.
- More permanent
- Cannot be escaped by changing provider
IP reputation
Tied to the server address your mail leaves from.
- Changes if you switch IPs
- A new IP has to be rebuilt from zero
What affects it
| Factor | Impact | What to aim for |
|---|---|---|
| Spam complaints | Critical | Below 0.1%, or 1 complaint per 1,000 emails. Even 0.3% is concerning. Send only to opted-in people and make unsubscribing easy. |
| Spam trap hits | Critical | Zero. Traps exist to catch poor practices and can get you blacklisted at once. Never buy lists. |
| Blacklist status | Critical | Not listed. A listing on Spamhaus, Barracuda or SURBL can block delivery to whole domains. |
| Engagement | Very high | Opens, clicks, replies and forwards show people want your email. Deletes without reading count against you. |
| Bounce rate | High | Below 2% overall. Hard bounces point to bad lists or spam traps. See email bounce rate. |
| Authentication | High | SPF, DKIM and DMARC all in place. Missing records raise red flags. |
| Volume and consistency | Moderate | Steady sending. Sudden spikes, or long gaps followed by huge blasts, look suspicious. |
| Content | Moderate | Subject lines that match the email. No piles of links or all caps. |
| Sending history | Cumulative | New domains and IPs have no history and need a warm-up of 4 to 8 weeks. |
How to build a reputation
A new domain or IP starts with no reputation at all. Building one takes patience:
Set up authentication first
Publish SPF, DKIM and DMARC before you send anything. It is the minimum providers expect.Warm up gradually
Increase volume over 4 to 8 weeks, starting small. Adjust the pace to your engagement and bounce rates.Start with your most engaged subscribers
Send early mail only to people who recently opened or clicked. Strong engagement at the start builds trust fastest.Use double opt-in
Confirm every new address before it joins your list. It keeps spam traps out from day one.Send on a regular schedule
Daily or weekly, not sporadic blasts. Consistency is what providers learn to trust.Deliver what you promised
Your first emails set the tone. Good engagement on them speeds everything up.Watch your metrics
Track bounces, complaints and engagement during warm-up. If they slip, slow down and clean your list.
Warm-up plan
news.acme.com · emails per day
- Week 1200 to 500
- Week 2500 to 1,000
- Week 31,000 to 5,000
- Week 45,000 to 10,000
- Week 510,000 to 20,000
- Week 620,000 to 50,000
- Week 750,000 to 100,000
- Week 8+Full volume
Keeping it healthy
Clean your list every 6 to 12 months
Run a re-engagement campaign for inactive subscribers and remove those who do not respond. Remove hard bounces immediately and soft bounces after 3 to 5 attempts.Make unsubscribing easy
Add a clear one-click unsubscribe to every email, process it immediately without a confirmation step and honour it permanently. People who cannot unsubscribe mark you as spam instead.Segment and personalize
Targeted email to the right group gets far more engagement, and engagement protects reputation.Separate transactional and marketing mail
Send receipts from transact.yourdomain.com and newsletters from news.yourdomain.com, so a marketing problem never blocks a password reset.
Transactional
transact.acme.com
Marketing
news.acme.com
What to check, and how often
| Metric | Target | Check |
|---|---|---|
| Delivery rate | 98% or more | Weekly |
| Spam complaint rate | Below 0.1% | Weekly |
| Bounce rate | Below 2% | Weekly |
| Opens and clicks | Steady or rising | Weekly |
| Blacklist status | Not listed | Monthly |
| Sender Score | 80 or higher | Quarterly |
Recovering a damaged reputation
Recovery is possible, but it takes time and discipline.
Find the cause
Look at recent campaigns for complaints, bounces and weak engagement, and check whether you are blacklisted. Fix the underlying problem first.Clean your list hard
Remove bounced addresses, unengaged subscribers and anyone who has not opened in 6 months or more. The list shrinks; quality matters more than size.Cut volume
Reduce sending by 50 to 70% and send only to your most engaged subscribers until trust returns.Request delisting
Find out which blacklists you are on, fix what got you there, then use each list’s removal process. Be honest about what you changed.Send email people want
Lead with useful content, not promotions. Engagement is what shows providers you have changed.Be patient
Recovery typically takes 4 to 12 weeks of consistent good behaviour. Do not return to full volume before your metrics do.
Tools to monitor reputation
| Tool | What it shows |
|---|---|
| Google Postmaster Tools | Free. Domain reputation, spam rate, authentication and encryption for mail sent to Gmail. |
| Microsoft SNDS | Smart Network Data Services: how Microsoft sees your IPs, including spam complaints. |
| Sender Score (Validity) | Free 0 to 100 score from industry data. The common benchmark for IP reputation. |
| MXToolbox Blacklist Check | Whether your domain or IP is on a major blacklist. Check regularly to catch listings early. |
| Talos Intelligence | Cisco’s sender reputation data for your IP, with a delisting request process. |
| BarracudaCentral | Reputation and blacklist status on Barracuda’s network. Important for enterprise delivery. |
Reputation starts with authentication. Use the DMARC checker to confirm your domain has a valid policy, and read the email deliverability guide for the rest of the picture.