How to Correctly Format Your Email Address

How to Correctly Format Your Email Address

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What do social media sites, free product samples, and weekly newsletters have in common? 

They all want your email address.

Just as a license is essential for navigating daily life, an email address is a must if one wants to enjoy all the internet has to offer.

And just as there are rules when obtaining a license (as anyone who has ever dealt with the DMV knows), an email address adheres to its own set of standards, standards that ensure mail is being delivered to the correct place. 

Of course, there’s a dark side to all of this. What if some of the email addresses that were used to sign up for your newsletter are fraudulent? How do you make sure an address is correct and, well, actually exists? When invalid email addresses find their way into your database, they can run amok, costing you time and money. 

This blog post gives you a quick history of the email address, lays out guidelines for creating one, and goes into how NeverBounce can help you verify addresses. 

History of the email address

The very first iteration of the email address came about in 1970 in the form of an internal computer messaging system at MIT. Since the communicating computers were local, there was no need to get fancy with email addresses-- at the time, they consisted of a username, the @ symbol, and the name of the computer that was intended to receive the message. 

As the internet became more like the internet we know today and the Domain Name System (DNS) rose to prominence, naming conventions changed to account for the slew of new locations which one could direct a message.

From there, Internet Service Providers (ISPs) and email hosting sites came to the fore. Electronic mail as we know it today was born, and providers such as AOL, Hotmail, and Yahoo helped shape the online scene. 

Today, there’s a score of different email providers one can choose from, and over four billion people worldwide have an active email account (source). This increase in usage has encouraged a change in naming conventions, detailed below.

Anatomy of an email address

The syntax of an email address is determined by Requests for Comments (RFC) documents, published by the Internet Engineering Task Force and the Internet Society. Together, they set standards for the usage of the Internet at large. RFC 5322 concerns itself with electronic mail, or email (source).

At the most basic level, an address must follow the rules below in order to be considered deliverable.

Username (local-part)

The username, or the local-part, can be up to 64 characters long and consist of any combination of letters, numbers, or other 7bit ASCII special characters (more on those later).

Periods are also acceptable in the local-part, provided they’re not the first or last character and they aren’t consecutive.

Domain name

The domain part of the address is subject to stricter guidelines. It can’t be more than 255 characters in length, and must adhere to the following specifications:

  • It must match the requirements for a hostname (the name of a device connected to a computer network)
  • Names must be fewer than 63 characters long and can contain Latin letters, the numbers 0 through 9, and hyphens. 

@ symbol

This is the glue that holds the address together. By including the @ symbol, you allow your email program to recognize the first half of your address as the username and the second half as the domain name. Without it, you simply don’t have an email address! 

.com, .org, .net, etc.

This is the cherry on top of the email sundae. Due to the potential for security risks, a domain without a dot com/net/etc ending is prohibited by ICANN (Internet Corporation for Assigned Names and Numbers). 

Sometimes, an email address outside of the United States will have an additional component after the dot com. For instance, a Canadian email address may read: 


Display name

This is the name that appears in the recipient’s inbox. (For example: Jane Doe <>.) Since this designation makes it easy to see with just a glance who has sent an email, we recommend setting your display name up ASAP. 

This can also be the name of a company or department.

Special characters and punctuation

Here, we’ll debunk some myths about email addresses that have become widely-held beliefs. 

Avoid some special characters to avoid risking rejected emails.

Due to the way many programmers set up mail systems, there are certain characters to be avoided in the local-part of an address for the sake of safety. Commas, asterisks, carets, and apostrophes have the potential to confuse email systems and render a message undeliverable. Typically, users won’t have to worry about this, as many email providers won’t let them use these characters in a username in the first place.

The period in a Google account doesn’t matter.

It’s true! Google ignores any periods in the username of an email address, so and are the same. Even if a person registers as your address, they’ll still receive emails sent to

Please note that this only applies to Google accounts. In many other email providers, such as Outlook or Yahoo, periods do matter, and the spelling at the time of signup should match what the user originally registered as their username. 

Addresses are not case sensitive

What this means is that if someone registers the account, it’ll still be read by the system as They can sign up for other services with JANEDOE or jANEdOE (and so on), but they’ll still receive email at janedoe@gmail. Email servers read addresses the same way as long as the letters and numbers match up; case doesn’t come into play at all. This is the case across providers such as Gmail and Yahoo.

Avoid these email addresses

Just because an email is valid doesn’t mean it’s beneficial to have on your mailing list. Here are a couple varieties of emails you want to avoid having on your list: 

Role addresses

As their name implies, these addresses are not assigned to a single person but to an entire department at a company, such as info@company or sales@company. You’d think that this means your message is sent to each person in that company’s department. In reality, it’s more than likely that the account is manned by a single person-- or a few people-- who screen emails and determine their relevance. Open rates may be lower than usual, so it’s best to leave these addresses alone. 

Spam traps

These wily inboxes may be real, but their purpose is to catch spammers in the act. Set up using valid, active email servers and designed to avoid detection, spam traps have a sleeper effect on your campaign-- which is to say, you won’t know you’re taking a hit until it’s too late. 

An email verification service such as NeverBounce is a reliable way to find spam traps. Typically, you won’t realize that anything is wrong on your own. 

How to validate an email address syntax with NeverBounce

An invalid email address can cause a host of troubles for your company. 

Bounce rate, ISP rating, etc -- you can end up in the spammer’s den. 

An email address may be invalid for a variety of reasons, such as the ones below:

  • An account that used to be valid but has been closed by the ISP or owner.
  • Bad data given to you from a data provider or other third party.
  • The email was typed in wrong.
  • A user gave you an invalid address on purpose.

So how do you make sure you’re sending messages to emails that both exist and benefit your company? 

NeverBounce’s real-time email verification ensures the cleanliness of your mailing list. Multiple connection methods -- from a custom API to a JavaScript widget -- let you customize your plan of attack. 

Plus, you can verify millions of emails from a host of different sources such as contact and lead forms, CRMs, and more. You can even automate the verification process so you can have confidence that your emails will not bounce every time you press send.

NeverBounce ensures you never send to a dirty list again. Try It Free

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