How to Add an Alias in Gmail: Send Email From a Different Address

Gmail's alias feature lets you send and receive email using a different address — all without leaving your main Gmail account. Whether you're managing a side project, keeping work and personal email separate, or using a custom domain address, understanding how aliases work in Gmail helps you figure out whether the setup fits your situation.

What Is a Gmail Alias?

An email alias is an additional email address that routes messages to your existing inbox. In Gmail's terminology, this is called "Send mail as" — it lets you compose and reply to emails using a different "From" address while everything lives in one Gmail account.

There are two distinct things people mean when they say "Gmail alias":

• A Google Account alias — an alternate address Google automatically assigns (like adding dots or a +tag to your existing address). These require no setup but offer limited control.
• A custom "Send mail as" address — an address you own (another Gmail, a Google Workspace account, or a custom domain) that you manually add to Gmail so you can send from it.

Most people asking how to add an alias in Gmail are looking for the second type: adding an external or alternate address so it appears as a selectable "From" option when composing.

How to Add a "Send Mail As" Alias in Gmail

The process runs through Gmail Settings on desktop (the mobile app doesn't support adding aliases — you'll need a browser).

Step 1: Open Gmail Settings

1. Click the gear icon in the top-right corner of Gmail
2. Select "See all settings"
3. Navigate to the "Accounts and Import" tab

Step 2: Add the New Alias Address

Under the section labeled "Send mail as", click "Add another email address".

A new window will open asking for:

• Name — the display name recipients will see
• Email address — the alias address you want to send from
• A checkbox for "Treat as an alias" — leave this checked if both addresses belong to you and you want Gmail to recognize incoming mail to that address automatically

Step 3: Verify Ownership

Gmail will send a verification email to the address you entered. You'll need to either:

• Click the confirmation link in that email, or
• Enter the numeric code it contains back into Gmail

This step confirms you actually own or control that address.

Step 4: Configure SMTP (For Non-Gmail Addresses)

If you're adding a non-Gmail address — like a custom domain address (e.g., [email protected]) — Gmail will ask for SMTP server details before verification. This includes:

Your email host or domain registrar provides these details. Without correct SMTP settings, Gmail can't send as that address — it can only receive mail forwarded from it.

Step 5: Set a Default (Optional)

Once verified, the alias appears in your "Send mail as" list. You can:

• Set it as your default sending address
• Or leave your primary Gmail as default and select the alias manually when composing

When composing a new email, click the "From" field to switch between your addresses.

The "Treat as an Alias" Setting — What It Actually Does

This checkbox causes confusion. Here's what it controls: 🔍

• Checked (alias mode): Gmail treats the address as truly yours. When someone replies to an email sent from that address, Gmail may automatically suggest replying from the same address. It also affects how Gmail matches incoming mail.
• Unchecked: Gmail treats it as a separate account you're accessing. Useful if you're checking a colleague's account or a shared inbox where you don't want Gmail conflating the two identities.

For personal aliases and your own addresses, leaving it checked is usually the right call.

Factors That Change the Experience

How smoothly alias setup works depends on a few variables:

Account type matters. Personal Gmail accounts and Google Workspace (business) accounts handle aliases slightly differently. Workspace admins can assign multiple alias addresses to a user account directly from the Admin Console — those aliases don't require the SMTP verification process and behave more natively.

Custom domains add complexity. Using Gmail to send as a custom domain address requires your hosting provider to support SMTP access and may require generating an app-specific password if two-factor authentication is enabled on that account. Some hosts restrict SMTP relay in ways that block this setup entirely.

Security settings on the alias account. If the address you're adding uses strict security (like a corporate account), IT policy may prevent Gmail from authenticating via SMTP — meaning the verification step will fail regardless of what you enter.

Number of aliases. Personal Gmail accounts can send as up to 99 aliases, though practical limits depend on whether you can actually authenticate each one.

What Aliases Can and Can't Do

Where Individual Setup Diverges 🧩

The steps above work for most standard configurations, but the path from "I want an alias" to "it's working reliably" looks different depending on what kind of address you're adding, who controls that address, and what your email host allows.

A personal Gmail-to-Gmail alias is the simplest case. A custom domain alias routed through a third-party host with two-factor authentication and strict SMTP policies is several steps more involved — and whether that process is smooth or frustrating depends almost entirely on the specifics of your hosting environment and account permissions.