How to Check a List of Proton Mail Addresses at Once (Bulk, Free)
A list of Proton Mail addresses can be checked in one pass for syntax, typo domains, dead domains and duplicates, but the mailbox itself can only be confirmed when Proton's server gives a clear answer. The bulk Proton Mail checker runs that pass in your browser, then asks Proton's server about the first 10 addresses live. Sign in with Google for the free checks on the rest.
Proton publishes no reference for what its servers answer, so an unclear reply is reported as risky and never as valid.
What works and what doesn't
In our verification study of October 2026 Proton rejected a made-up address with a "mailbox not found" reply. On a Proton list the checker reliably catches broken syntax, typo domains such as protonmial.com, domains with no mail server, throwaway domains and duplicates. The single-address version is covered in how to verify a Proton Mail address.
The by-hand way
- Sort the list by domain and pull out proton.me, protonmail.com, protonmail.ch and pm.me.
- Remove repeats and obvious typos.
- Test addresses one at a time with a single-address checker.
Step 1: paste the list
Paste addresses one per line, or a CSV column. Addresses at other providers go in too; they are checked as normal addresses and marked.
Step 2: read the flags and download
Look at typo domains, duplicates, +tag repeats and dead domains. Download the clean list; only rows that fail a check come off.
Step 3: the live answer
The first 10 addresses, Proton rows first, go to the mail server without sending anything.
What this check cannot do
- Custom domains with a catch-all address come back risky: where it is on, a made-up address is accepted too, so no single address there can be confirmed. Proton describes the setting in its catch-all help.
- Only proton.me, protonmail.com, protonmail.ch and pm.me are matched by name.
- A +tag repeat is marked as possibly the same inbox, not merged.
- Valid means the mailbox exists today, not that anyone reads it.
Next: the rest of the list
For a whole list of any size, use the verify page: the first 100 checks are free with a Google sign-in, no card. See also bulk email verification.
Try it now
Paste your list into the bulk Proton Mail checker.
Common questions
Can you verify Proton Mail addresses in bulk?
Partly. Syntax, typo domains, dead domains and duplicates are flagged for the whole list, and the first 10 addresses are asked live at Proton's mail server. Proton publishes no reference for its replies, so an unclear answer stays risky.
Why do some Proton addresses come back risky?
Proton doesn't publish how its servers answer a mailbox check, and custom domains can catch all mail. When Proton gives no clear answer, the checker reports risky rather than guessing valid.
Are proton.me, protonmail.com and pm.me the same service?
Yes. They are Proton Mail domains, and the tool counts all of them, plus protonmail.ch, as Proton rows.
Are company domains hosted at Proton matched?
No. They are checked as normal addresses and marked as another provider.
Will the people on my list know I checked?
No. The check ends after the mail server answers about the mailbox, before any message content is sent.
Check your list before you send
Real mailbox checks over SMTP, and nothing is sent to the address. Sign in with Google and your first 100 email checks are free, no card. Plans for bigger lists are on the pricing page.