Your email reputation is the judgement mailbox providers have formed about your sending. It decides whether your next campaign lands in an inbox or a junk folder.
You can’t see it directly. What you can see are the signals behind it, so check those in five free tools and move them.
Key Takeaways
- What it is: a provider’s running judgement of your sending, held at domain and IP level.
- A good score: above 90 is excellent, 70 to 89 is fine, 50 to 69 is at risk, below 50 means blocking is routine.
- Check it in Postmaster Tools, SNDS, Sender Score, MxToolbox and Talos. No single tool covers everything.
- Fix it in stages. Stop the damage, clean the list, rebuild engagement, reintroduce sending. Weeks, not days.
- Keep it with authentication, list hygiene and consistent volume. Recent behaviour outweighs history.
What is Email Reputation?
Email or sender reputation is a trust score that mailbox providers like Gmail, Outlook, and Yahoo score you on how recipients respond to your mail and how your infrastructure is set up, and they recalculate that score constantly.
It sits at two levels. Domain reputation is yours. IP reputation belongs to whoever owns the sending IP, which on Google Workspace or Microsoft 365 isn’t you.
What Is the Role of Sender Reputation?
It decides placement before anyone looks at your content. A trusted sender clears filters a new domain won’t, sending the same message. That’s why two identical emails from two domains land in different folders.
What a Good Email Reputation Score Looks Like
Most tools score out of 100, and the bands below hold broadly across them. The exact number still moves from tool to tool.
| Score | Rating | What it means in practice |
|---|---|---|
| 90 to 100 | Excellent | Consistently reaching the primary inbox |
| 70 to 89 | Good | Mostly fine, occasional spam placement |
| 50 to 69 | At risk | Filtering is already happening. Act now |
| Below 50 | Poor | Blocking and spam placement are routine |
Track the trend on one tool rather than comparing a Sender Score number to a Talos one. They measure different things and disagree by design.
How to Check Email Reputation
Five free tools, and none of them covers everything. That’s the honest framing, and why you need two or three rather than one.
Free Tools to Check Your Reputation
| Tool | What it shows | Covers | Cost |
|---|---|---|---|
| Google Postmaster Tools | Domain reputation, spam rate, authentication, delivery errors | Personal Gmail only | Free |
| Microsoft SNDS | IP-level complaint and filter data | Outlook.com | Free |
| Sender Score | An IP reputation score out of 100 | Cross-provider, IP only | Free |
| MxToolbox | Blocklist status across dozens of lists, plus DNS and MX records | Cross-provider, no inbox data | Free |
| Talos Intelligence | Domain and IP reputation, blocklist status | Cross-provider | Free |
Two limits on that table almost no guide states.
Postmaster Tools covers consumer Gmail, not Workspace. Google says so outright. Data there applies only to mail sent to personal Gmail accounts, meaning gmail.com and googlemail.com addresses.
So if your recipients sit on business domains, it tells you nothing about them. It also needs volume before any data shows up.
SNDS reports on IP addresses, and only ones you control. Send through a shared platform and the IP isn’t yours to register, which closes the tool to you. It also stopped reporting spam trap hits in July 2026.
A lookup on your blocklist status covers ground none of the five does. The metrics behind the score explains what each number counts.
How Often Should You Check It?
Weekly while you’re actively sending, and monthly otherwise. Check again straight after any change to volume, sending domain, authentication or list source. One reading on its own tells you very little.
How to Fix Email Reputation
How to Tell if Reputation Is Already Damaged
- Placement falling while bounce rate holds steady → reputation, not list quality
- Postmaster domain reputation showing amber or red
- Sudden spam placement on a provider that was fine last week
- Deferrals and 421 responses appearing in your logs
One rule sits above all of these. If you’re blocklisted, delisting comes before anything else on this page. Nothing below works while a listing is live.
The Recovery Plan
Change one thing at a time, and expect weeks rather than days.
| Stage | Duration | What you do | Advance only when |
|---|---|---|---|
| 1. Stop the damage | Immediately | Pause cold sending. Delist if blocklisted. Fix authentication | Records pass and no active listing |
| 2. Clean and shrink | 3 to 5 days | Verify the list. Remove anything unverified or unengaged | Bounce rate under 2% on a test send |
| 3. Rebuild engagement | 2 weeks | Warmup only, no campaigns. Low volume, high reply rate | Reputation trending up for 5 consecutive days |
| 4. Reintroduce sending | 2 weeks | Small volume to your most engaged segment, warmup continues | No spam placement, complaints under 0.1% |
| 5. Return to volume | 2 to 4 weeks | Ramp gradually, never more than 20% a day | Stable at target volume for two weeks |
*Durations above are guidance drawn from recovery patterns, not measured averages.
Volume comes down before anything else goes up. Stage 3 runs on warmup. That’s the mechanism that rebuilds sending history when you’ve none of your own to show.
And a judgement nobody else will offer you. A domain with repeated blocklist history is often slower and dearer to recover than to replace.
Listed more than once? Warming a replacement domain is usually the cheaper path.
What Determines Email Reputation
Providers weight these differently and none publishes its formula, so the order below is observed rather than official.
The split that matters: complaints and engagement are things recipients do. Authentication and infrastructure are things you control.
| Factor | Weight | The signal you’ll see |
|---|---|---|
| Spam complaints | Critical | Complaint rate above 0.1% |
| Recipient engagement | Critical | Replies falling while volume holds |
| Bounce rate | Critical | Above 2% |
| Authentication | High | SPF, DKIM or DMARC failing or misaligned |
| Sending volume and consistency | High | Placement drops after a volume change |
| Sending infrastructure | Medium | Swings you can’t explain, on a shared IP |
| Content signals | Medium | Promotions rather than spam, Gmail specifically |
Recent behaviour outweighs history. A clean sender degrades in days; a damaged one recovers in weeks.
Spam Complaints
The fastest-moving negative signal you have. Google asks senders to stay under 0.1%, and the damage is graduated from there rather than switching on at a line. At 0.3% a bulk sender becomes ineligible for delivery mitigation.
Recipient Engagement
Replies, and to a lesser extent clicks, tell providers a human wanted the message. Silence across a whole segment reads as mail nobody asked for.
Bounce Rate
Keep it at or below 2%. Above that, reputation drops from high to medium, because invalid addresses read as a list nobody maintains. Fixing bounces is list work, not sending work.
Authentication
SPF, DKIM and DMARC get checked on every message. Failing or misaligned records aren’t a small penalty. They’re a reason to distrust everything else about the send.
Sending Volume and Consistency
A steady pattern is worth more than a large one. Spikes after quiet periods look like a compromised account, which is what providers watch for.
Sending Infrastructure
On Workspace and Microsoft 365 you share an IP with thousands of other tenants and inherit their behaviour. You can’t control it, which is why domain reputation is the part worth your attention.
Cold email infrastructure covers the setup, and cold email service providers covers handing it to someone else.
Content Signals
The weakest of the seven. Content mostly decides Promotions versus primary at Gmail rather than inbox versus spam. A trusted sender clears copy a new domain won’t.
How to Improve Email Reputation? 10 Best Practices
The section above was for a reputation already damaged. This one is for a healthy one you want to keep.
The sequence matters. Infrastructure first, because nothing downstream works without it, then list quality, then sending behaviour. None of this moves the number overnight.
Use Separate Sending Domains and Rotate Them
Send outreach from domains other than the one your invoices go out from. Cold sending degrades a domain over time, so rotation is normal rather than evasive. A problem on one then stays contained.
Authenticate Your Email Domain
Publish SPF, DKIM and DMARC for every sending domain before the first send. A domain that fails authentication starts every campaign behind.
Use an Email Warmup Service
A new domain has no sending history, and providers read silence as suspicion. Warmup builds that history through real conversations, so your first campaign isn’t also your first impression.
Compare warmup tools if you’re choosing one.
Include an Unsubscribe Link
Give people an exit. Marketing and promotional mail sent to personal Gmail at volume requires one-click unsubscribe. Every other message benefits from one anyway, because the alternative is the spam button.
Personalise Your Outreach Emails
Relevance is the difference between a reply and a complaint. A message that could have been sent to anyone gets treated as though it was. Personalisation covers what actually moves reply rate.
Regularly Clean Your Email List
Remove hard bounces immediately and unengaged addresses on a schedule, because every dead address you keep mailing signals a list nobody is watching. Better still, start from a clean list.
Rotate Sending Accounts
Spread volume across mailboxes rather than pushing one hard, which most cold email software will do for you. Rotation only protects reputation if every mailbox in it is warmed. That’s the part people skip.
Monitor Email Deliverability Metrics
Watch inbox placement, complaints, bounces and authentication pass rate weekly. A trend across thirty days is worth more than any single campaign reading. The deliverability checklist lists what to watch.
Do Not Track Open Rates
Opens are measured by a 1×1 pixel that fires when images load, and that mechanism broke in both directions.
Providers increasingly don’t load images from unfamiliar senders, so a read email registers as unopened. Apple Mail Privacy Protection prefetches images whether or not anyone reads. Corporate security gateways do the same when they scan, which is the B2B one.
The result is scanners mixed in with people, and no way to tell them apart. Track reply rate and positive reply rate instead. Both need a human to act.
Conduct an Email Deliverability Audit
Run a full pass quarterly and after any infrastructure change. An email deliverability audit catches what a dashboard never reports, including the servers nobody thinks of as mail servers.
Close
Reputation is the judgement underneath every placement decision, and it moves on recent behaviour rather than history. That cuts both ways: a clean sender can degrade within days, and a damaged one can recover within weeks.
Check it weekly on one tool, watch complaints and bounces first, and change one thing at a time when the number falls. Blocklisted more than once? Ask whether the domain is worth recovering at all.
Frequently Asked Questions
What Is a Good Email Reputation Score?
Above 90 is excellent, and below 50 means blocking and spam placement are already routine. Between 50 and 70 is the warning band. Tools score differently, so track the trend on one rather than comparing tools.
How Do I Check My Email Reputation for Free?
Google Postmaster Tools for personal Gmail, Microsoft SNDS for Outlook.com, and Sender Score, MxToolbox or Talos for a cross-provider view. All five are free.
None covers every provider, so most senders need two or three. None reports where your mail actually landed either. For that you need seed testing.
How Often Should I Check It?
Weekly while you’re actively sending, monthly otherwise, and straight after any change to volume, sending domain, authentication or list source. The trend across several weeks is what providers themselves look at.
How Do I Fix a Damaged Email Reputation?
Stop sending, fix authentication, delist if you’re blocklisted, then rebuild engagement through warmup at low volume before campaigns come back. Expect weeks rather than days.
The common mistake is changing several things at once, which leaves you unable to tell which one worked.
How Long Does It Take to Repair Email Reputation?
Content and consistency problems correct within days once behaviour changes. Damage from complaints or bounces takes several weeks of steady sending.
A domain with blocklist history can take months. One listed repeatedly is often faster to replace than to recover.
Is Sender Reputation the Same as Domain Reputation?
Not quite. Sender reputation is the overall judgement, built from domain reputation and IP reputation together. On Google Workspace or Microsoft 365 you share an IP you don’t control, so domain reputation is the part you can actually influence.
