What Is the Maximum Email Address Length?

Yep, there's an upper limit

Email logo on key on keyboard

 

TARIK KIZILKAYA / Getty Images

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 that we use today. The maximum length of an email address based on this format is 254 characters, although there has been some confusion about this matter. 

Character Limitations in an Email Address

Every email address consists of two parts. The user name comes before the @ sign, and the domain name follows it. In "person@company.com," the user name 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 stated that the user name must not exceed 64 characters, the domain name is limited to 255 characters, and the @ sign is one character.

If you add these up, you arrive at 320. But, wait, that's different from the 254 figure we mention above. Here's why: the current standard says that the maximum total length of an email address can be 256 characters, including the punctuation. Some addresses, however, use angle brackets, which take up two characters, leaving the maximum number of characters you can use in an email address at 254.

When you create your user name, you can 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 !#$%&'*+-/=?^_`{|}~.

Bottom line: when creating an email address, limit the user name to 64 or fewer characters, and the total number of characters to 254. Of course, anyone corresponding with you will likely think the shorter you can make it, the better.