email basicsParts of an Email Address: Local Part, @ and Domain Explained

The parts of an email address are the local part, the @ sign and the domain, written as local-part@domain (RFC 5322, section 3.4.1). That's the whole anatomy of an email address. Everything else you may have heard of, such as a subdomain, a TLD or a plus tag, sits inside one of those three parts.

Take jane@example.com:

• Local part: jane, the part before the @. It names the mailbox.
• @ sign: the separator between the two halves.
• Domain: example.com, the part after the @. It names where the mail goes.

Looking for the parts of an email message (subject line, greeting, body, signature)? That's a different topic; this guide covers the address itself. For the message side, our post on writing email subject lines is a place to start.

The parts of an email address at a glance

Here are all the parts of an email address in one longer example:

first.last+news@mail.example.co.uk
└─────┬───────┘│└───────┬────────┘
  local part   @      domain

Part	In the example	What it is	Also called
Local part	first.last+news	The part before the @; it names the mailbox at the domain	Username or handle (informal)
Plus tag	+news	An optional tag inside the local part	Subaddress
@	@	The separator between local part and domain	At sign
Domain	mail.example.co.uk	Everything after the @	Email domain
Subdomain	mail	An extra label to the left of the domain name	–
Domain name	example	The name that identifies the organization	–
TLD	uk	The last label; this address ends in the TLD .uk	Top-level domain, domain extension

co in this example is one more label between the domain name and the TLD. You don't need to name it to read the address: it's part of the domain, which ends in .uk.

So when someone asks what the parts of an email address are called, the short version is: local part, @ and domain. The other names in the table describe pieces of those three.

The local part (the part before the @)

The first part of an email address is called the local part. It names a mailbox at the domain, and the receiving domain's mail system decides what it means: which inbox, group or forwarding rule it leads to. People often call it the username or handle, but those are informal terms; the standards say "local part".

In first.last@example.com, the local part is first.last. Companies usually build it from an employee's name in a fixed pattern, and our guide to company email formats shows the common ones and how to find a company's pattern.

Which characters you can use in the local part, and how long it can be, are covered in our valid email address format rules. This page only names the parts.

Plus tags (subaddressing)

Some addresses add a tag to the local part with a plus sign: name+tag@example.com. On Gmail, mail to janedoe+school@gmail.com is delivered to janedoe@gmail.com, and Google notes that these aliases aren't private (Google Help).

Other providers handle plus tags in their own way, so check with yours before you rely on one.

The @ sign

The @ separates the local part from the domain. Everything to its left is the local part, and everything to its right is the domain. In an everyday address there's exactly one @.

The domain (the part after the @)

What is the domain of an email address? It's everything after the @. In jane@example.com, the domain is example.com: the name that identifies where the mail goes.

Who controls the domain depends on the address. On a free provider such as gmail.com, the provider owns the domain. On a company address such as jane@example.com, the organization owns it.

Domain name, subdomain and TLD

A domain is made of labels separated by dots, and each label uses letters, digits and hyphens (RFC 5321, section 4.1.2). Reading the labels from right to left:

• TLD (top-level domain): the last label, such as .com or .uk. TLDs are delegated in the DNS root zone, and IANA's root zone database lists them by type, such as generic (.com) and country-code (.de).
• Domain name: the label in front of the TLD (or in front of labels like co in example.co.uk), such as example.
• Subdomain: an extra label to the left of the domain name. mail.example.co.uk has the subdomain mail.

Many addresses have no subdomain at all: jane@example.com is just a domain name and a TLD.

Email domain vs buying a domain for business email

If you searched "email domain" because you want an address on your own domain, such as you@yourcompany.com, that's a question for a domain registrar or an email-hosting provider. This guide explains what the domain in an address is, not how to get one.

What is not part of the address

Email apps often show a name next to the address, like this:

Jane Doe <jane@example.com>

Jane Doe is the display name, and the address is only what's inside the angle brackets: jane@example.com. The standard defines this as an optional display name followed by the address in < and > (RFC 5322, section 3.4). The display name and the brackets are not part of the email address.

When a form asks for your email address, it wants only the address: jane@example.com, without the name or the brackets.

Symbols you can and cannot use (overview)

Here is the short version of which symbols an email address can contain:

• @ once, as the separator between local part and domain.
• Dots between words in the local part, as in first.last, and between labels in the domain.
• Letters and digits in both parts.
• Some special symbols in the local part, such as +, _, - and ', are allowed by the standard (RFC 5322, section 3.2.3).
• Spaces and commas are not allowed (outside of rare quoted forms).

Providers are often stricter than the standard. Gmail usernames, for example, can contain only letters, numbers and periods (Google Help).

For the exact rules, the length limits, hyphen details and a regex, see our guide to the valid email address format.

Examples: label the parts yourself

Cover the right-hand columns and try to name the parts of each address first.

Address	Local part	Domain	TLD
jane@example.com	jane	example.com	.com
first.last@example.co.uk	first.last	example.co.uk	.uk
orders+2026@shop.example.com	orders+2026 (plus tag +2026)	shop.example.com (subdomain shop)	.com
Jane Doe <jane@example.com>	jane	example.com	.com
name@gmail.com	name	gmail.com	.com

In the fourth row, Jane Doe is the display name. The address is only jane@example.com, inside the angle brackets.

A correct structure does not mean the mailbox exists

nobody-here@example.com has a local part, an @ and a domain, and mail sent to it can still bounce. Knowing the parts tells you an address is put together correctly, not that anyone reads it.

To find out whether an address works, check it with the free email verifier, which checks that the domain can receive mail and that the mailbox exists. Some domains are catch-all and accept mail for any address, so a single mailbox there can't be confirmed. For all the ways to check an address, see how to check if an email is valid.

FAQ

How many parts does an email address have? Three: the local part, the @ sign and the domain, as in jane@example.com. Subdomains, the TLD and plus tags are pieces of the local part or the domain.

What is the part before the @ called? The local part. People also call it the username or handle, but those are informal terms.

What is the part after the @ called? The domain. In jane@example.com, the domain is example.com.

Is the TLD part of the domain? Yes. The TLD is the last label of the domain, such as .com in example.com or .uk in example.co.uk.

What is a subdomain in an email address? An extra label to the left of the domain name. In jane@mail.example.co.uk, the subdomain is mail.

Is the display name part of the email address? No. In Jane Doe jane@example.com, Jane Doe is the display name and the address is only what's inside the angle brackets.

What does the plus sign do? It adds a tag to the local part, as in name+tag@example.com. On Gmail, mail to janedoe+school@gmail.com reaches janedoe@gmail.com. Other providers vary, so check with yours.

Check whether the address works

Knowing the parts is one thing; whether the mailbox exists is another. Check an address with the free email verifier, no signup (5 free checks per hour).

Checking a whole list? Sign up for 200 free validations, no credit card needed.