Deliverability drops, replies slow down, and someone on the team has to work out where the problem sits: with the IP addresses the mail leaves from, or with the domain it’s sent as. Most guides answer that question for teams that run or rent their own sending servers. Many B2B teams don’t.
IP reputation is the trust a mailbox provider attaches to the address of the server sending your mail, and every sender using that address shares it. Domain reputation is the trust attached to the domain in your From address and your DKIM signature, and it follows you when you change providers or IPs. Gmail and Yahoo score both, and neither publishes how it weighs one against the other. For teams sending from Google Workspace or Microsoft 365, though, the IPs belong to Google or Microsoft, which means the domain is the reputation they actually control.
In this article, we’ll define each type of reputation and look at why mailbox providers increasingly lean on the domain. We’ll then cover which reputation B2B teams can realistically influence and how list quality affects it, how to track both now that Gmail has retired its reputation charts, and when IP reputation becomes yours to manage.
Key takeaways
- IP and domain reputation attach to different things. IP reputation belongs to the address of the server sending your mail. Domain reputation belongs to your From domain and its authentication, and it moves with you when you change providers or IPs.
- Providers score both and don’t publish the weighting. Gmail and Yahoo track reputation for IPs and domains, and Gmail’s delivery errors name a low IP reputation and a low domain reputation as separate causes.
- Workspace and Microsoft 365 senders effectively manage one reputation. They send from IPs their provider controls, so the domain is nearly the only reputation they can affect, and bounces and spam trap hits from a poor list land directly on it.
- Gmail’s reputation charts are gone. Google announced it would retire the domain and IP reputation dashboards in Postmaster Tools, and by late August 2026 they had disappeared. Reputation now has to be read from bounces, spam rate, delivery errors and rejections.
- A dedicated IP only pays off at high, steady volume. Below that, it concentrates risk on an address with no shared history to absorb mistakes, rather than giving you more control.
What is IP reputation, and how does it differ from domain reputation?
Mailbox providers judge every message on two identities at once: the server it came from and the domain it claims to be from. Each has its own reputation, built from different signals and owned by different people.
The overlap matters. Bounces and spam trap hits damage both reputations at once, while complaints and authentication failures attach to the domain.
What is IP reputation?
IP reputation is the trust a mailbox provider assigns to the IP address your email is sent from. It’s built from that address’s sending volume, bounce rate, complaints and spam trap hits. Every sender using the same IP shares it, which is why a shared IP can carry problems that someone else caused.
What is domain reputation?
Domain reputation is the trust attached to the domain in your From address and your DKIM signature. It’s built from how recipients respond to your mail, your complaint and bounce rates, and whether your SPF, DKIM and DMARC authentication passes. Because it’s tied to the domain rather than the server, it follows you across providers and IPs. Our domain reputation guide covers how to improve it.
Opens aren’t part of the picture. Google’s sender guidelines state that Google doesn’t track open rates, and that user spam reports can lower your domain’s reputation. Beyond spam reports, providers typically read engagement from what recipients do with a message: replying to it, moving it out of spam, or deleting it unread.
Domain reputation isn’t entirely yours to control either. If your domain doesn’t enforce DMARC, anyone can send mail that appears to come from it, and complaints about that mail may count against you. A DMARC policy set to quarantine or reject is what stops that, which is one reason enforcement matters beyond the authentication requirements themselves.
Why are email providers prioritizing domain reputation?
Mailbox providers have been putting more weight on the domain for three practical reasons.
First, IPs are easy to change and domains aren’t. A sender can move to a new IP in an afternoon, or have its email provider move it without notice, while a domain carries its history for years. Scoring the domain gives providers a signal that a bad sender can’t shed by switching servers.
Second, shared IPs blur who did what. When many senders use the same address, a complaint against that IP can’t tell a provider which of them caused it. The domain ties the behavior to one sender.
Third, recipients judge the From domain, not the server. Their replies and spam reports are reactions to the sender they can see.
The providers’ own published guidance points the same way. Yahoo’s sender best practices state that “each IP and DKIM domain has a reputation”, and that authentication gives senders “a consistent reputation for their domain, regardless of which IP mail is sent from.” Authentication itself is now enforced at the domain level. Gmail has required SPF or DKIM from every sender since February 2024, and DMARC from anyone sending more than 5,000 messages a day. Since 5 May 2025, Microsoft has rejected mail from senders of more than 5,000 messages a day to Outlook.com, Hotmail.com and Live.com that fails these checks, with the error 550 5.7.515.
None of these providers publishes how it weighs domain reputation against IP reputation, and IP reputation hasn’t gone away. Gmail’s list of delivery errors still includes “Sending IP has a low reputation” alongside “Sending domain has a low reputation”. An IP on a blocklist that a provider honors can stop mail before the domain is even considered.
Which reputation can B2B teams actually control?
Most guides to this comparison assume you run or rent your own sending servers. Many B2B sales teams don’t. If your reps send from Google Workspace or Microsoft 365 mailboxes, either directly or through a sales engagement platform connected to those mailboxes, the mail usually leaves from Google’s or Microsoft’s IPs. You can’t warm those IPs, monitor them or move off them, and Microsoft’s SNDS won’t register them, because access requires proving you own the IP range.
Google’s sender guidelines draw the line clearly: “DKIM and SPF quotas are specific to your domain,” while “the IP address quota is shared for all senders that use that IP address.”
That means for these teams, IP reputation is the provider’s problem and domain reputation is theirs. Three things remain under their control: (1) the domain’s authentication, (2) how it sends (volume, pacing and consistency), and (3) the quality of the list it sends to.
List quality is where domain reputation often breaks down without anyone noticing. Hard bounces from invalid addresses, spam trap hits on stale or purchased data, and catch-all addresses that accept mail with nobody behind them all count against the sending domain. With Gmail’s reputation charts gone and Microsoft removing trap counts from SNDS in July 2026, most of that damage now stays invisible until inbox placement drops.
That’s why protection has to happen before the send. Allegrow verifies contacts automatically before they are sent, including conclusive valid or invalid results on catch-all and gateway-fronted company domains, where many verifiers return “unknown”. Safety Net then stops risky contacts inside your sales engagement platform at the moment of send. To check a single address you’re unsure about, our free email verifier works without signup.
Some teams also isolate cold outreach on a secondary sending domain, so their main domain isn’t exposed. Our guide to email subdomain best practices covers how to set that up.
How to track and measure domain and IP reputation
The way you track reputation changed in 2026. Google announced it would retire the domain and IP reputation dashboards in Postmaster Tools, and by late August 2026 Mailgun reported that the charts had disappeared and the link to the old interface had stopped working. Postmaster Tools v2 keeps the other dashboards (spam rate, authentication and delivery errors) and adds a Compliance dashboard. Google has said a new reputation view will follow, but it hasn’t given a date.
Gmail still scores your reputation. You just can’t see the score anymore. Our Google Postmaster Tools guide walks through what v2 shows. Until a replacement arrives, you have to read reputation from these signals:
Treat blocklist lookups as an early warning rather than a final answer. Many listings carry little weight with the large mailbox providers, and some lists charge for removal. For more on Microsoft’s side, see our guide to Microsoft SNDS.
If you send from Google Workspace or Microsoft 365, the IP-side rows don’t apply to you. You don’t own the IPs, so there’s nothing to look up or register. That means your reading of reputation comes almost entirely from bounces, rejections and spam rate, which makes keeping those numbers clean before the send even more important.
Allegrow covers part of the gap Gmail left. It tracks your domain’s health and reputation from its own measurements, so you still have a reputation reading without the Postmaster charts. It also monitors your SPF, DKIM and DMARC records every hour, so a broken record is caught before it shows up as rejected mail. And because providers read engagement as a trust signal, Allegrow’s automated positive email interactions with real B2B inboxes can help a domain build and hold its standing between campaigns.
Shared vs dedicated IPs: when IP reputation becomes yours to manage
On a shared IP, your provider manages the IP’s reputation and pools it across many senders. That works well for most teams at low to moderate volume, as long as the domain is well run. A dedicated IP hands IP reputation to you: you warm it, pace it and monitor it, and nobody else’s sending affects it.
That only pays off at high, steady volume. SendGrid’s guidance is that once you reach 250,000 messages a month, you should use at least two dedicated IPs, one for marketing and one for transactional mail. At larger scale, it recommends one dedicated IP for every three to four million messages a day.
Below that kind of volume, a dedicated IP concentrates risk rather than adding control. Every mistake lands on an IP with no shared history to absorb it, and irregular sending makes it harder for providers to build trust in the first place. Our comparison of dedicated vs shared IPs covers the decision in more detail.
Conclusion
IP reputation belongs to the server your mail leaves from, and domain reputation belongs to you. Mailbox providers score both, and none of them publishes how it weighs one against the other. What the providers do publish points the same way: authentication is enforced per domain, and the domain’s reputation follows you whichever IP you send from.
For teams sending from Google Workspace or Microsoft 365, the domain is the reputation they actually own, because the IPs belong to their provider. With Gmail’s reputation charts gone and Microsoft’s trap counts removed, damage to that domain now tends to show up only when placement drops. That makes protecting it before the send more important than reading it afterward, starting with the list.
To see where your list stands, start a 14-day free trial and run up to 1,000 of your own company and catch-all contacts through Allegrow before your next send. You’ll see which addresses would have bounced against your domain, including the ones other verifiers return as “unknown”.
FAQs
Does a dedicated IP improve inboxing on its own?
No. A dedicated IP gives you control over your sending infrastructure, but without a clean list, aligned authentication and steady volume, that control works against you. A poorly warmed or irregularly used dedicated IP can do more harm than a well-run shared pool, because nothing else absorbs its mistakes.
Can you still check domain reputation in Google Postmaster Tools?
Not at the moment. Google announced it would retire the domain and IP reputation dashboards, and by late August 2026 they had disappeared from Postmaster Tools. Version 2 shows compliance status, spam rate, authentication and delivery errors instead. Google has said a new reputation view will follow but hasn’t given a date.
Do subdomains have separate reputations from the root domain?
Subdomains maintain their own reputation profiles, but providers still consider the interconnected history of the root domain. Using different subdomains for different mailing streams allows you to isolate reputational risk, but it does not erase poor domain history. This technique is often used to protect critical streams like transactional email while maintaining aggressive marketing outreach elsewhere.
Should I change IPs if my inbox placement drops suddenly?
Changing IPs can sometimes provide temporary relief, especially if the old IP was blacklisted or strongly damaged. But without fixing underlying issues, such as list hygiene, engagement, authentication, or spam-trap exposure, you risk regenerating the same problem on the new IP. Because domain reputation travels with you across IPs, it’s often more effective to focus on domain-level fixes before switching infrastructure. If you send from Google Workspace or Microsoft 365, changing IPs isn’t an option, so the domain is where the fix has to happen.
How can you check your IP reputation and spot blocklist issues?
For IPs you own, run blocklist lookups and register them with Microsoft SNDS to see filtering results at Outlook.com and Hotmail. Treat most blocklist listings as early warnings, since many carry little weight with the large providers. Teams sending from Google Workspace or Microsoft 365 don’t have an IP reputation of their own to check.
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