How do I verify a Fastmail Business email address?

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

Does the Fastmail Business verifier detect full mailboxes?

Yes, our 16-point engine identifies if a Fastmail Business inbox is over capacity, which is a common cause of hard bounces.

DIRECT_MX_ACCESS: @fastmail.com

Verify Fastmail Business emails with 98% accuracy.

Fastmail Business offers hosted business email services associated with fastmail.com, including managed mailboxes, admin controls, and professional deliverability features. It is commonly used for account sign-ups and password resets for organizations operating in Global.

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

Domain Target

@fastmail.com

Industry

Business Email

Handshake Speed

< 50ms Avg

Security Audit

ISO 27001 / SOC2

Instant Fastmail Business 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 Fastmail Business to ensure the recipient infrastructure is active and capable of receiving external traffic.

Mailbox Integrity

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

Reputation Protection

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

Common Questions About Fastmail Business Verification

Is it safe to verify @fastmail.com emails?

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

How accurate are the results for Fastmail Business?

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

Can I verify Fastmail Business emails in bulk?

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