Email Reputation Check: Steps in Order

What does an email reputation check actually measure?

There's no single reputation score that Gmail, Outlook and Yahoo all use. Each receiving server keeps its own internal judgement of your sending domain and sending IP, and you never get to see it directly. An email reputation check gathers the outside signals that feed into that judgement or reflect it.

• Authentication: does SPF authorise the server that sent the mail, does a DKIM signature from your domain verify, and does DMARC find at least one of them aligned with the domain in the From header? This is the easiest part to check, because the receiving server writes the result into the message header.
• Domain reputation: how mailbox providers rate mail signed by your domain, based on recipient complaints, bounces and engagement. Google shows part of this in Postmaster Tools.
• IP reputation: how blocklists and providers rate the IP address the mail came from. On a shared IP, that rating reflects every sender in the pool.
• Your own logs: hard bounces, spam complaints and unsubscribes recorded in your sending account. No outside tool sees these as precisely as you do.

For the broader picture of how reputation gets built and repaired, see our guide to sender reputation. This article covers running the check itself, in the order that wastes the least time.

How to run an email reputation check, step by step

Start with the signals you control and move towards the ones you can only observe. If authentication fails, nothing further down the list is worth reading yet.

1. 1 Send a test mail from your real sending setup to a Gmail address you own. Open it, choose Show original, and read the Authentication-Results header. You're looking for spf=pass, dkim=pass with d= set to your own domain, and dmarc=pass. If DKIM passes but the signature belongs to your email provider's domain rather than yours, it doesn't count towards DMARC alignment.
2. 2 Check your published DNS records. You need exactly one SPF TXT record at the root of the domain, a DKIM key at the selector your provider gave you, and one DMARC TXT record at _dmarc. Duplicate SPF records or duplicate DMARC records make the check fail. They don't get merged.
3. 3 Open Google Postmaster Tools for your domain. You verify ownership with a DNS TXT record. Read the spam rate and domain reputation dashboards. Google only shows data once your daily volume to Gmail users is high enough, so an empty dashboard means there isn't enough data, not that your reputation is clean.
4. 4 Look up your sending domain and sending IP on the Spamhaus reputation checker and on Cisco Talos Intelligence. A listing tells you something specific happened. No listing tells you very little.
5. 5 Run a multi-blocklist lookup, for example on MXToolbox, to see whether smaller lists have picked up your IP or domain.
6. 6 Pull bounce and complaint data from your Brevo account for your recent campaigns. Remove hard-bounced addresses before the next send and look for complaint clusters by list source.

Our free SPF, DKIM and DMARC checker reads the published records for your domain, so you can do the second step without typing dig commands.

Which email reputation check tool covers which signal?

No single tool covers everything, so choose by the question you're asking. Every row below uses the same yardstick: what the tool checks, what you need before you can use it, and where it stops.

Tool	What it checks	What you need	Where it stops
Google Postmaster Tools	Domain reputation, spam rate and authentication results for mail sent to Gmail users	A domain verified by a DNS TXT record	Gmail recipients only; no data below Google's volume threshold
Microsoft SNDS	Data on mail from your IP addresses to Outlook.com users	Control of the sending IP address	Can't be used for a shared IP you don't own
Spamhaus reputation checker	Whether an IP or domain appears on Spamhaus blocklists	Nothing; public lookup	Shows listings, not a positive rating of your mail
Cisco Talos Intelligence	Reputation lookup for IPs and domains	Nothing; public lookup	Reflects Cisco's own data sources, not what Gmail or Outlook decide
MXToolbox blacklist check	Listings across many public blocklists at once	Nothing; public lookup	Many small lists carry little weight with large mailbox providers

Seed-list placement tests and list verification services answer different questions. You'll find them in our overview of email deliverability tools by job.

Why does an IP reputation check mislead on a shared Brevo IP?

Unless you've added a dedicated IP to your Brevo account, your mail goes out from IP addresses that Brevo shares across many customers. When you look up that IP on Spamhaus or Talos, you're seeing the pool's history. A poor result can come from someone else's campaign, and a clean one proves nothing about your own list.

Your domain is what travels with you. Your DKIM signature and From address put it on every message, and mailbox providers build domain reputation on that basis. That's why the check order above starts with domain-level signals: DKIM signed by your domain, DMARC alignment, and Google Postmaster Tools data for that domain. Microsoft SNDS works by IP, so on a shared IP it won't show you anything about your own sending.

One thing that doesn't work is switching to a new sending domain to get away from a bad reputation. The new domain has no history, which receiving servers treat cautiously, and the list and sending habits that caused the problem move across with you.

What does a bad result mean, and what won't fix it?

• dkim=pass but dmarc=fail: the DKIM signature comes from your provider's domain, not yours. Publish the DKIM key your provider gives you for your own domain.
• spf=permerror: usually two SPF records, or one record whose includes trigger too many DNS lookups. Merge everything into a single record.
• Postmaster spam rate rising: recipients are clicking Report spam. The cause is usually list source or how relevant the message is. Rewording the subject line won't stop complaints from people who never expected to hear from you.
• Spamhaus domain listing: often triggered by mail to spam traps, which tend to come from bought or scraped lists. If you get delisted without cleaning the list, you'll usually end up listed again.
• High hard-bounce rate in Brevo: the list has invalid addresses on it. Verify the list before you import it, and suppress every hard bounce straight away.

If your mail is already landing in spam, our article on why emails go to spam goes through the fixes in order. How the receiving server makes its decisions is covered in what decides cold email deliverability.

Do sales follow-up emails affect your email reputation?

Yes. Every follow-up is another message signed by your domain, and it adds to your sending volume and your complaint exposure exactly like the first email does. Here's how the common follow-up questions tie back to reputation.

• Sales follow up email template: reply in the original thread so the In-Reply-To header links it to your first message. Add one line of context, one specific question and a plain opt-out sentence. For example: "Hi Anna, following up on my note about onboarding videos for your sales team. Is this something you're looking at this quarter? If not, just say so and I won't follow up again."
• Follow up sales email: a second message to someone who hasn't replied. To the receiving server it's just more mail from your domain, so following up with an address that hard-bounced, or with someone who has already said no, puts your reputation at risk.
• Cold email deliverability: the receiving server decides it, based on SPF, DKIM and DMARC results, your domain and IP reputation, bounces and complaints. Follow-ups are part of the volume it looks at.
• Sales email follow up templates: keep separate versions for no reply, after a call, and a final close-the-loop message. Don't put a fake "Re:" on a message that isn't really a reply. It misrepresents the message and it won't thread.
• Sales follow up email: stop after a hard bounce, an unsubscribe or a clear no. Several jurisdictions, Germany among them, require prior consent before you send advertising emails, B2B included, so silence never counts as permission.
• Sales follow up email examples: after a call, "Thanks for your time today. As agreed, I'll send the pilot outline by Thursday. Does Friday afternoon still work to go through it?" After no reply, a one-line nudge in the same thread that asks a single question.

You'll find more copy-ready versions in our sales follow up email templates.

How EmailFlow OS sends, and why it matters for your reputation check

EmailFlow OS is our own product. You record one video and upload it to EmailFlow OS, connect your Brevo account and sending domain, and import your prospect list into EmailFlow OS. It then turns that single recording into a personalised version for each recipient (per person, not per company) and sends each version from your own inbox, through your own Brevo account and your own domain. It never sends through a shared platform sender.

For your reputation check, that means every signal above stays yours to read. The DKIM signature and From domain are your own, the Google Postmaster Tools data for your domain includes these sends, and bounces and complaints show up in your Brevo account. EmailFlow OS doesn't decide inbox placement. The receiving server does, so the checks in this article apply in exactly the same way. The home page explains how personalised video email with EmailFlow OS works.

Questions people ask

? Is there a free email reputation check?

Yes, several. Google Postmaster Tools, the Spamhaus reputation checker, Cisco Talos Intelligence and the MXToolbox blacklist check are all free. Each covers a different signal: Postmaster shows how Gmail sees your domain, while Spamhaus and MXToolbox only show blocklist listings. For a free authentication check, read the Authentication-Results header of any message that reaches a Gmail inbox you own.

? What is the difference between domain and IP reputation?

IP reputation belongs to the address the mail was sent from. Domain reputation belongs to the domain in your DKIM signature and From header. On a shared IP, the IP rating covers many senders, while the domain rating covers only mail that carries your domain. That makes domain reputation the signal you can actually influence.

? Why is my Google Postmaster Tools dashboard empty?

Google only shows data once a domain sends enough daily mail to Gmail users, and the dashboard doesn't state the exact threshold. Small cold outreach volumes often leave it empty. That means there isn't enough data, not that your reputation is good. Check the authentication headers and your Brevo bounce logs instead.

? How often should I run an email reputation check?

Check authentication before every new campaign and after any DNS change, because a single broken SPF or DKIM record makes every send fail DMARC. Check Postmaster Tools and blocklists on a regular schedule, and right away when replies drop or bounces rise. Review bounce and complaint logs after every send.