Early email systems tried several different email formats. Only one has survived, and that is the familiar [email protected] (where TLD is the top-level domain, such as .com, .org, .net, and .gov) format that is used today. The maximum length of an email address using this format is 254 characters, although that was not always the case.
What is the maximum length of a valid email address?
Every email address consists of two parts. The username comes before the @ sign, and the domain name follows. In "[email protected]," the username is "person" and the domain name is "company.com."
The total length of an email address in the original standard was 320 characters. The standard limited the username to 64 characters and the domain name to 255 characters. (If you do the math, that comes out to 319. The last character is the @ symbol in between.)
This 320-character limit differs from the 254-character limit because the current standard limits the total length of an email address to 256 characters, including punctuation. However, some addresses use brackets (<>), which take up two characters, keeping the maximum number of characters in an email address to 254.
