What Is the Maximum Email Address Length?

There's an upper limit on the number of characters in an email address

Email logo on key on keyboard

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In early email systems, several email formats were tried. Only one survived, though, and that's the familiar username@entity.tld (with TLD being the Top Level Domain such as .com, .org, .net, and .gov) format used today. The maximum length of an email address based on this format is 254 characters, although there's been some confusion about this matter. 

Character Limitations in an Email Address

Every email address consists of two parts. The username comes before the @ sign, and the domain name follows it. In "person@company.com," 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.

When added together, the character limit is 320. This limit is different from the 254 figure because the current standard limits the total length of an email address to 256 characters, including punctuation. Some addresses, however, use angle brackets, which take up two characters, leaving the maximum number of characters used in an email address at 254.

When creating a username, use uppercase letters A to Z and lowercase letters a to z, as well as the digits 0 to 9, a single dot (as long as it isn't the first or last character), and other special characters such as !#$%&'*+-/=?^_`{|}~.

When creating an email address, limit the username to 64 or fewer characters, and the total number of characters to 254. However, the shorter the email address, the easier it is for people to remember.