Email Validation Tool
Check whether an address is real before you send to it.
An email verification service that checks whether an address exists and can receive mail — syntax, domain and MX records, mailbox existence, disposable and role addresses — one at a time or across a whole list. Built and operated by RNS STAR LLC.
Key features
- Syntax, domain and MX record validation
- Mailbox existence checks against the receiving mail server
- Disposable, role and catch-all address detection
- Bulk list cleaning with CSV upload
- REST API for validating at signup
FAQ
What does the Email Validation Tool do?
It tells you whether an email address is real and able to receive mail, before you send to it — checking the address format, the domain and its MX records, and whether the mailbox itself exists.
Why does validating a list matter?
Sending to dead addresses produces bounces, and a high bounce rate damages your sender reputation, which then hurts delivery to your genuine subscribers. Cleaning the list first protects the rest of your sending.
Can I validate addresses automatically?
Yes. A REST API lets you check an address at the moment someone signs up, so invalid addresses never enter your list in the first place.