What is Email Validation?
Email validation checks whether an email address follows the correct format and structure. It verifies syntax rules like having an @ symbol, proper local part, valid domain format, and acceptable characters.
Note: Format validation confirms an email looks right, but can't verify if it actually exists or receives mail. That requires actually sending to the address.
Email Structure
Emails have two parts: local (before @) and domain (after @). The local part can include letters, numbers, and characters like . + - _. The domain must be a valid hostname with a TLD.
Example: john.doe+newsletter@mail.company.com - 'john.doe+newsletter' is local, 'mail.company.com' is domain.
What This Validates
The validator checks:
- Presence of @ symbol
- Non-empty local and domain parts
- Domain has at least one dot
- No spaces in the address
- Length limits (64 char local, 255 char domain)
Frequently Asked Questions
What does email validation check?
Email validation checks the format/syntax of an email address - proper structure (local@domain), valid characters, and domain format. It does NOT verify if the mailbox actually exists or can receive mail.
Can validation guarantee an email works?
No. Format validation only checks syntax. An email can be syntactically valid but non-existent. Verifying deliverability requires actually sending a message or using email verification services.
What makes an email address valid?
A valid email has: local part (before @) with letters, numbers, and certain symbols; @ separator; domain with valid hostname format; TLD (like .com). Example: user.name+tag@sub.domain.com
Are plus signs (+) valid in emails?
Yes! Plus addressing (user+tag@domain.com) is valid. Many services use this for email filtering. Gmail and others support it natively.