How do I know if a company uses Proofpoint?

Look up the domain's MX records. A first MX host ending in pphosted.com means mail goes through Proofpoint. The email provider lookup and MX lookup tools show it for any domain.

Are domains behind Proofpoint catch-all?

Some are and some aren't; it depends on how each company configured Proofpoint. A verifier can tell by offering a random address that can't exist: if the domain accepts it, the domain is catch-all and single addresses there can't be confirmed.

What is pphosted.com in an MX record?

It is Proofpoint's hosted email security service. A domain with MX hosts under pphosted.com sends its inbound mail through Proofpoint's filters before it reaches the company's own mail server.

Security gateway · Proofpoint

Verifying addresses at domains behind Proofpoint

Can you verify addresses at domains behind Proofpoint?

Depends on the domain

It depends on the company. Domains behind Proofpoint are probed like any other.

Proofpoint answers for the company's own mail rules, so the checker treats every domain on its own: it offers a random address first, and if that is accepted the domain is catch-all and results come back risky ("Accepts all addresses"). Otherwise your address gets a per-mailbox answer. It always checks the syntax, the domain's MX records, disposable domains and role addresses such as info@ first.

Reasons you'll see in results:Mailbox existsMailbox not foundAccepts all addresses

Email address

Five checks a minute, no account needed. Nothing is sent to the address — we ask its mail server whether the mailbox exists, then disconnect.

Companies whose MX points at a pphosted.com host filter inbound mail through Proofpoint, so a mailbox check talks to Proofpoint rather than the company's own server. Whether it rejects unknown recipients depends on how the company loads its user list. Where it accepts any address, results come back catch-all.

Live DNS snapshot: proofpoint.com

Checked 21 October 2026, 07:21 UTC

pphosted.com is an MX host suffix, not a mail domain, so this is proofpoint.com: a domain whose mail runs through Proofpoint. Read from DNS at the time shown and refreshed at most once a day.

MX4 hosts

10mxa-00148501.gslb.pphosted.comProofpoint
10mxb-00148501.gslb.pphosted.comProofpoint
15mx0a-00148501.pphosted.comProofpoint
15mx0b-00148501.pphosted.comProofpoint

First MX host belongs to Proofpoint.

SPFPublished

v=spf1 include:%{ir}.%{v}.%{d}.spf.has.pphosted.com ip4:91.209.104.0/25 a:spf-mailers.proofpoint.com include:i.ppops.net include:_spf.atlassian.net ~all

DMARCPublished

p=reject: meets the requirement and enforces it.

v=DMARC1; p=reject; sp=reject; fo=1; rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ruf=mailto:dmarc_ruf@emaildefense.proofpoint.com

Look up any other domain with the MX lookup or the email provider lookup.

Proofpoint at a glance

Operated by	Proofpoint, Inc.Source: Proofpoint Essentials getting started guide
MX hosts	Hosts under `pphosted.com`, usually `mxa-<id>.gslb.pphosted.com` and `mxb-<id>.gslb.pphosted.com`, as on proofpoint.com itselfObserved 20 October 2026 (dig MX proofpoint.com)
Address rule	Proofpoint Essentials, the small-business product, uses `ppe-hosted.com` MX hosts such as `mx1.us2.ppe-hosted.com`Source: Proofpoint Essentials getting started guide
Address rule	Essentials users are loaded by directory sync, CSV import, manual entry or SMTP Discovery; with SMTP Discovery on, unregistered addresses can receive mail at onceSource: Proofpoint Essentials getting started guide

Why Proofpoint-protected domains can be catch-all or per-mailbox

Proofpoint filters mail before it reaches the company's own server, so the check talks to Proofpoint, not the mailbox. How it handles unknown recipients depends on how its user list is built. Proofpoint's Essentials setup guide offers directory sync, CSV import, manual entry and SMTP Discovery.

With a synced directory, the gateway knows the real users and can turn unknown ones away. With SMTP Discovery on, the guide says unregistered addresses can receive mail straight away. Proofpoint's enterprise documentation for pphosted.com sits behind a customer sign-in, so this page states only what the Essentials guide documents and what our checker does by design.

What our checker does behind Proofpoint

SimpleVerifier doesn't skip or special-case Proofpoint. For each company domain it offers a random address that can't exist, then your address, and disconnects without sending. If the random address is accepted, the domain is catch-all and its results come back risky with "Accepts all addresses". If it is rejected, your address gets a real answer for that mailbox.

Proofpoint Essentials domains (ppe-hosted.com) are a separate product with their own MX hosts and user-list setup. Check the MX host before assuming which product a company runs.

Cleaning a list full of Proofpoint domains

Split the list by domain, not by platform. Two companies on Proofpoint can behave in opposite ways, so a catch-all result at one says nothing about the next. The bulk catch-all checker finds which domains in a list accept everything before you spend time on single addresses.

For catch-all domains, keep addresses with recent replies or sign-ups and send the rest in a small first batch, suppressing anything that hard-bounces. For per-mailbox domains, trust the verdict: invalid addresses will bounce, and valid ones were accepted by the company's own directory. Accept-all vs unknown results covers the difference.

Common questions

Can you verify addresses at domains behind Proofpoint?: It depends on the company. Domains behind Proofpoint are probed like any other. Proofpoint answers for the company's own mail rules, so the checker treats every domain on its own: it offers a random address first, and if that is accepted the domain is catch-all and results come back risky ("Accepts all addresses"). Otherwise your address gets a per-mailbox answer. It always checks the syntax, the domain's MX records, disposable domains and role addresses such as info@ first.
How do I know if a company uses Proofpoint?: Look up the domain's MX records. A first MX host ending in pphosted.com means mail goes through Proofpoint. The email provider lookup and MX lookup tools show it for any domain.
Are domains behind Proofpoint catch-all?: Some are and some aren't; it depends on how each company configured Proofpoint. A verifier can tell by offering a random address that can't exist: if the domain accepts it, the domain is catch-all and single addresses there can't be confirmed.
What is pphosted.com in an MX record?: It is Proofpoint's hosted email security service. A domain with MX hosts under pphosted.com sends its inbound mail through Proofpoint's filters before it reaches the company's own mail server.

Catch-all checkerTest whether a domain accepts any address before you trust a valid.

Bulk catch-all checkerFind the catch-all domains in a whole list at once.

Email provider lookupName the mailbox provider or gateway behind a domain.

Bulk provider lookupGroup a list's domains by Google, Microsoft, gateway and the rest.

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