Email Validator

Validate email address syntax, check MX records, and detect common issues.

What This Validator Checks

RFC 5322 Syntax
The email format conforms to the internet email standard.
Address Length Limits
Local part ≤64 chars, domain ≤255 chars, total ≤254 chars.
TLD Validity
Top-level domain must be alphabetic and at least 2 characters.
No Consecutive Dots
Double dots (..) are invalid in email addresses.
Disposable Domain Detection
Flags addresses from known throwaway email services.
MX Record Lookup
Checks DNS to verify the domain can actually receive email.

Frequently Asked Questions

Does this tool verify that the mailbox actually exists?

No. Confirming mailbox existence requires sending a real email and checking for a bounce. SMTP probing (RCPT TO verification) is blocked by most modern mail servers to prevent email harvesting.

Why might a real email address fail the MX check?

MX lookups can fail due to temporary DNS issues or unusual configurations. Some valid domains use A records instead of MX records. A failed MX check is a warning, not definitive proof the address does not exist.

What is the maximum length of an email address?

RFC 5321 limits the whole address to 254 characters. The local part (before @) is limited to 64 characters. The domain is limited to 255 characters.

Does this tool store the email addresses I enter?

No. Email addresses are used only to perform the validation checks in real time and are not stored, logged, or shared with any third party.