Our email validation tool is built based on the following validation processes:
- Standard RFC Email Validation.
- DNS Records Validation.
- Message-ID (RFC2822) Validation.
Email syntax is shown as follows: local part + @ + domain part
Local part
The local part can be up to 64 characters in length and consist of any combination of alphabetic characters, digits, or any of the following special characters:
! # $ % & ‘ * + – / = ? ^ _ ` . { | } ~
NOTE: The period character (“.”) is valid for the local part subject to the following restrictions:
- It is not the first or last character
- Two or more consecutive periods
Domain part
The domain part cannot be more than 255 characters in length and must conform to the specification for hostnames which is a list of dot-separated DNS labels. Each DNS label must not exceed 63 characters and should consist of any combination of alphabetic characters, digits, and hyphens.
NOTE: A couple of restrictions apply to the DNS label:
- Top-level domains cannot be all numerics.
- Hyphens cannot be the first or last character.
Internationalization
With the introduction of Internationalized Domain Names, non-ASCII characters can now be used in both the local as well as domain parts of an email address. UTF-8 characters are used to represent non-ASCII characters such as Chinese & Japanese characters.