Mailthentic vs Proofy
A verifier that shows its working, from the SMTP code to the confidence score
Proofy is an established email verification provider and a recognisable option for teams cleaning lists. If you are looking at alternatives, the most productive thing you can do is stop comparing marketing claims and start comparing what each tool actually reports back to you.
We are not going to say anything about their product. Their current pricing is on their own site. This page is about what Mailthentic does.
Know what verification can and cannot prove
Every verifier hits the same wall. A catch-all domain, also called accept-all, is configured to accept mail for every address at that domain. When a mail server behaves that way, nobody can confirm from the outside whether one particular mailbox behind it exists.
The same is true of the two biggest mailbox providers. Gmail and Google Workspace, and Outlook and Microsoft 365, return 250 OK during an SMTP conversation even for addresses that do not exist. An accepting response from them proves the domain will take the mail, not that the person is there.
So the real question when you evaluate a verifier is simple: what does it do with the addresses it cannot prove? Does it tell you, or does it round them up into "valid" and hand you a report that looks better than reality?
What Mailthentic reports
Catch-all and unconfirmable addresses come back as catch-all or unknown with a confidence score. That is deliberate. We would rather give you an accurate picture of your risk than a flattering percentage.
Every single result explains itself. Each row shows the status, the reason for that status, the raw SMTP response code that the receiving server returned, and a confidence score. You can audit any address, which means you can defend any decision you make from the data.
The full detection stack runs syntax validation, domain and MX record checks, disposable domain detection, catch-all detection, role based flagging for addresses like info@ and admin@, and risky and invalid classification. Greylisting is handled properly: 421, 450 and 451 are temporary deferrals, so we retry with a backoff instead of discarding an address that was never actually bad.
The practical side
There is a full API and bulk CSV upload, with your original columns preserved on export, so results slot straight back into whatever you already run. CRM integrations cover Brevo, HubSpot, Salesforce, Mailchimp and PlusVibe: import a list, verify it, push the clean results back. We deduplicate before processing, so duplicates never cost you credits. Buy pay as you go credits that never expire, or take a monthly plan. Data handling is GDPR aligned, and we never sell, share or reuse your contacts.
What Mailthentic does
Exactly what you get, stated plainly. We do not fill in a column for Proofy, because their feature set is theirs to describe and it changes. Check their site and compare for yourself.
| Capability | Mailthentic |
|---|---|
| Data handling | GDPR aligned, contact data never sold, shared or reused |
| Detection stack | Syntax, domain and MX, disposable, catch-all, role based, risky, invalid |
| CRM integrations | Brevo, HubSpot, Salesforce, Mailchimp, PlusVibe |
| Per row explanation | Status, reason, raw SMTP response code, confidence score |
| Greylisting handling | Retried with backoff on 421, 450 and 451 |
| API and bulk CSV upload | Yes, original columns preserved on export |
| Catch-all reported honestly | Yes, catch-all or unknown, with a confidence score |
| Charged for duplicate addresses | No, deduplicated before processing |
Comparing the pricing
Verification pricing changes often, so rather than quote a number that may already be out of date, here are both pricing pages. Check them side by side.
Mailthentic
Pay as you go with credits that never expire, or a monthly plan. Duplicates in your list are removed before processing, so you are not charged for them twice.
See Mailthentic pricingProofy
Their pricing is theirs to state, and it changes. Check the current rates on their own site so you are comparing today's numbers, not ours.
See Proofy pricingWhy Teams Choose Mailthentic
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Results are fully explainable: every address carries a reason, an SMTP response code and a confidence score
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Catch-all domains are reported as catch-all rather than converted into confident valids
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We state plainly that Gmail, Google Workspace, Outlook and Microsoft 365 mailboxes cannot be confirmed by SMTP alone
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Deduplication before processing means you are only charged for unique addresses
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Greylisting is retried with backoff, so temporary deferrals do not cost you good contacts
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API, bulk CSV and CRM integrations with Brevo, HubSpot, Salesforce, Mailchimp and PlusVibe
Where Proofy Excels
We believe in honest comparisons. Here is where Proofy has advantages:
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An established provider with a recognised name in email verification
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A straightforward option that many teams have used for list cleaning
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A solid track record in the market
Is Mailthentic right for you?
Mailthentic is right for you if
- You want to see the reasoning. Every verdict comes with the reason and the raw SMTP code that produced it, so nothing is taken on trust.
- You send to business domains, where catch-all servers are common, and you would rather know that an address is unconfirmable than be told a comfortable half truth.
- You need the full detection stack, not just a syntax and MX check: disposable domains, role based addresses, catch-all detection, and risky and invalid classification all in one pass.
- Your list carries duplicates from years of imports, and you do not want to pay to verify the same address more than once.
- You want verification embedded in your workflow, through the API on a signup form, or through Brevo, HubSpot, Salesforce, Mailchimp or PlusVibe with the clean results written back.
- You prefer credits that never expire so a one off clean does not turn into an ongoing subscription.
Not the right tool if
- You are shopping for the report that shows the highest possible valid percentage. Ours will show you reality, which sometimes includes a substantial catch-all bucket.
- You need a complete outbound platform with prospecting and sequences bundled in. We do verification, deliberately.
Test it, do not take our word for it
Take a few hundred addresses from a real list, ideally with some known outcomes, and run them through both tools. Then compare the things that predict deliverability: how many valids are sitting on catch-all domains or on Google and Microsoft infrastructure, whether every result comes with an explanation you can check, and how many duplicate rows you were charged for. Pricing moves on both sides, so read Proofy's current pricing on their site and ours on the Mailthentic pricing page, and compare cost per unique address rather than per uploaded row.
Frequently asked questions
Is Mailthentic cheaper than Proofy?
Both providers adjust pricing over time, so compare the two directly: their current pricing is on their own site and ours is on the Mailthentic pricing page. The variable most people forget is duplicates. Because we deduplicate before processing and only charge for unique addresses, your effective cost depends on how much repetition your list carries. Work it out on a real sample of your own data.
Why can't you just confirm every address as valid or invalid?
Because some addresses genuinely cannot be confirmed. A catch-all domain accepts mail for every address at that domain, so an accepting response tells you nothing about a specific mailbox. We report those as catch-all or unknown with a confidence score. A tool that gives you a clean binary answer for every address is telling you something it cannot know.
How do you handle Gmail and Microsoft 365?
We check them and we are open about the limits. Both return 250 OK during an SMTP conversation even for addresses that do not exist, so an SMTP probe cannot confirm the mailbox. We apply the rest of our stack, syntax, domain and MX, disposable and role based signals, then report a status with a confidence score and a stated reason.
What is included in a result row?
The status, the reason for that status, the raw SMTP response code the receiving server returned, and a confidence score. On CSV export, your original columns come back alongside those fields so the file goes straight back into your existing process.
Does greylisting cause false negatives?
Not with us. A 421, 450 or 451 is a temporary deferral rather than a rejection, so Mailthentic retries with a backoff instead of marking the address as a failure. Discarding greylisted addresses is a quiet way to lose perfectly good contacts, and we avoid it.
What happens to my list after verification?
You get it back and we move on. Mailthentic is GDPR aligned and we never sell, share or reuse your contact data for any purpose, including building databases of our own.
Ready to try a better alternative?
Start with 1,000 free verification credits. No credit card required. See the difference for yourself.