How do I verify a ProtonMail (legacy) email address?

You can use our real-time tool to ping the protonmail.com mail servers directly. Our system checks the mailbox existence without sending an actual email.

Does the ProtonMail (legacy) verifier detect full mailboxes?

Yes, our 16-point engine identifies if a ProtonMail (legacy) inbox is over capacity, which is a common cause of hard bounces.

DIRECT_MX_ACCESS: @protonmail.com

Verify ProtonMail (legacy) emails with 98% accuracy.

ProtonMail (legacy) is a privacy- and security-oriented email provider offering persistent inboxes on protonmail.com, with an emphasis on encryption, reduced tracking, and user control. It is commonly used for account sign-ups and password resets for privacy-sensitive users in Global.

Perform a technical SMTP lookup of any @protonmail.com recipient to confirm mailbox existence without sending a single message.

Domain Target

@protonmail.com

Industry

Secure Email

Handshake Speed

< 50ms Avg

Security Audit

ISO 27001 / SOC2

Instant ProtonMail (legacy) Check

Enter an email address below to run a real-time verification via our primary 16-point engine.

Need to verify a full list? Click here.

Domain Health Check

We verify the MX record configuration for ProtonMail (legacy) to ensure the recipient infrastructure is active and capable of receiving external traffic.

Mailbox Integrity

Our cluster simulates an SMTP delivery attempt to @protonmail.com. If the mailbox is full, disabled, or non-existent, our engine flags it instantly.

Reputation Protection

Cleaning your Secure Email leads through our 16-point engine reduces bounce rates by up to 98%, keeping your sender IP off global blacklists.

Common Questions About ProtonMail (legacy) Verification

Is it safe to verify @protonmail.com emails?

Yes. Our process is non-intrusive. We use a technical SMTP handshake to communicate with ProtonMail (legacy) servers without ever sending a real message to the recipient.

How accurate are the results for ProtonMail (legacy)?

Our 16-point engine is optimized for Secure Email domain protocols, delivering 98% accuracy by detecting if the mailbox exists and can receive email.

Can I verify ProtonMail (legacy) emails in bulk?

Absolutely. You can upload a CSV or Excel spreadsheet containing thousands of @protonmail.com addresses to our list cleaning tool for instant processing.