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Are Email Addresses Case Sensitive?

Suppose someone writes down their email address for you, and they have capitalized some of the letters within it. In such an instance, you might wonder to yourself:” Are email addresses case sensitive?”

The simple answer is: no. Email addresses are not case-sensitive, so you can enter all the information in lowercase letters without affecting the address. In other words, if you input the correct characters in the email address, your message will be sent, even if it is in all caps.

We’ll help you decipher the importance of case sensitivity, how it applies to email addresses, and discuss email syntax in general. 

What Is Case Sensitivity?

When inputting data, sometimes information is case sensitive, indicating that the correct combination of uppercase letters and lowercase letters, as well as numbers and symbols, is essential. Inputting lowercase letters where uppercase ones are necessary can trigger an incorrect entry, even if the characters are correct.

An important example of this involves the use of passwords. You’ll often see a note next to many online password boxes letting you know that passwords are case-sensitive. Some even add humor to this phrase by rewriting it as “CaSe SeNsiTivE” to indicate that capital letters have different meanings in the password box.

When typing information in a case-sensitive input box, if your password is ToastandAvocado, typing toastandavocado would result in an incorrect password attempt. Even Toastandavocado or toastandAvocado would be wrong because each omits one of the vital case-sensitive letters.

In these situations, it is essential to write down your passwords with all the capitalization included so that you don’t get locked out of your account by forgetting to capitalize one or more letters!

Are Email Addresses Case Sensitive?

Email addresses are not case sensitive, indicating that you don’t need capitalization—just the proper ordering of letters and numbers. For example, if a user had the email address and you typed into the email address field, email service providers (also known as ESPs) would still accept this as the same email address.

They are not two mutually exclusive emails; they’re connected to the same person regardless of how you input them in the address box. In this case, the user of this email has probably chosen to display their email as JohnnyAppleseed because it’s easier to distinguish the recognizable words “Johnny” and “Appleseed” from one another rather than a jumble of lowercase letters (johnnyappleseed) that makes the meaning of the email address harder to decipher.

What Are the Crucial Parts of an Email Address?

Case sensitivity is a relatively unimportant part of an email address. Instead, it would be best to focus on ensuring you get the unique username (also known as the “local part”), domain name, and top-level domain correct. Without these three elements, your email will be lost in cyberspace—or not sent at all.

Username (or “Local Part”)

The username (or the local part) is your unique address and is the information that appears before the @ symbol. Getting the username right ensures your email goes to the right recipient. Millions of users have email addresses, so if you need to get someone’s address, have them write it down or text it to you so that you get the exact letters, numbers, and special characters included.

For instance, if someone tells you verbally that their email username is BrittanySmith, you might be shocked when the person who receives the email doesn’t recognize you at all. That may be because there are various ways to spell the name Brittany—Britnee, Brittany, Brittani, Brittanee, Brittanni, Britney.

Sure, some of these may be more uncommon than the regularly common spelling Brittany, but it is always good to confirm your email is going to the right place!

You should also pay special attention to any numbers in the email address. If someone tells you that their email address is CoaltoDiamonds, you might wind up sitting at your keyboard with a puzzled expression on your face when you head to the address box. Is the username CoaltoDiamonds or Coal2Diamonds? The only proper way of knowing is to ask the owner of the address to write it down.

It is a good idea to extend the same courtesy to others, especially if you’re using a play on words, numbers that could be confused for letters, or an abbreviated version of your name.

Domain Name (or Domain Part) and Top-Level Domain

The domain name appears before the @ symbol and gives the email server essential information about where the email is going. There are many email domain providers, including Yahoo, Gmail, and Microsoft Outlook, although plenty of custom domains exist.

The top-level domain is simply the email extension and can include .com, .gov, .net, and .org, among others. This part of the address goes directly after the domain name.

What is essential to remember is that after inputting the username, you need to add the @ symbol (the ampersand) followed by the correct domain name they have given you. After inputting the domain name, add a (.) and the appropriate extension (.com in most cases).

To illustrate, in our previous example of, this is how to break down the email address:

  • Unique username (Local Part) – JohnnyAppleseed1985 (Can also be written as johnnyappleseed1985)
  • Domain name (Domain Part) – Since the user has registered an email with Google, the domain is @gmail
  • Top-level domain – Gmail servers run on a .com extension, so the top-level domain is .com

At the end of the day, as long as you input the email address exactly the way the owner gave it to you, there’s little risk of misinterpreting or failing to include any necessary information in your email. Let’s hope that they wrote down their email address correctly!

Can You Include Special Characters or International Symbols in Your Username?

You can also use some special characters in your username, but not with all service providers. For example, a Gmail address will not allow an underscore (_), while a Yahoo one does. 

International symbols (characters from other languages such as Chinese or Russian). They are deciphered by using something called Unicode, which makes sure international characters are recognised by computer software. 

Many assume special characters cannot be used since the question mark symbol (?), hyphen (-), and several other symbols cannot be used in file names. This is not the case with email.

They can, however, be used with no issue in an email address, although you should keep in mind that Gmail completely disregards periods in the username, making it pointless to include them.

For all these reasons, it’s probably best to avoid too many special symbols, and to stick to Latin characters, if possible, in order to avoid any confusion. 

The Bottom Line

Email addresses are rarely case-sensitive, with only the oldest providers posing potential problems distinguishing between upper and lowercase letters. As long as you type in the email address in the address bar precisely as the person gave it to you, with all the appropriate parts, there should be no problems with your message reaching its intended target. And to further put everyone at ease—yes, this applies to Gmail, Hotmail, Yahoo and all other major email service providers. There is no need to worry about capitalization in your email addresses!


Posted by James Smith
By James Smith

Described as an "English Guru," James Smith holds a Master's degree in English from Arkansas Tech University, a Bachelor of Fine Arts in Creative Writing with a minor in ESL. James is a sought after writer and editor with University teaching experience.

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