How to properly add an alias to Gmail without errors (send mail as)

Over the years, I’ve changed domains a few times and managed multiple websites with their own emails. I always like everything in one Gmail inbox, as it makes it easy to keep track of things. Gmail has a handy “send mail as” feature, which lets you add multiple email addresses as aliases. This enables you to change the from and reply-to address. Below I’ll show you how to get past all the common errors.

How to add alias to Gmail

One of the reasons I’m documenting this is because Gmail’s instructions don’t mention everything, and then you wind up with errors. I typically find myself going through this every six months or so, and by then, I’ve forgotten all the little hiccups that can come up. I hope this helps save you some time.

Before we dive in, let me give you a use case scenario.

  • (my primary Gmail I use to manage everything)
  • (send mail as, alias #1)
  • (send mail as, alias #2)

Your primary Gmail can be a custom domain or a @gmail address. This depends on whether or not you are using G Suite. You can set up to 99 different “send mail as” and or alias email addresses. The alias email address can also be a @gmail address, it doesn’t have to be a custom domain.

This tutorial assumes you have 2-Step-Verification enabled on your Gmail account. If you don’t, you should.

If you’re using G Suite

If you’re using G Suite, you’ll need to follow a few steps first to add aliases within Gmail.

First, go to “Apps → G Suite → Gmail → End User Access.” Scroll down and enable “Allow per-user outbound gateways.”

G Suite allow per-user outbound gateways
G Suite allow per-user outbound gateways

Next, go to “Security → Settings → Less Secure Apps.” Enable “Allows users to manage their access to less secure apps.”

Allow less secure apps in G Suite
Allow less secure apps in G Suite

Note: This does make your account less secure, so beware of the changes. Google recommends setting up a domain alias in G Suite, which you can do. But this won’t let you pass the steps below, unfortunately. To change your “From” address, you have to set this up in Gmail, which requires an App password. Hopefully, this will change in the future.

After saving the above options, it will probably take 20-30 minutes to propagate the changes across to your Gmail. Grab a coffee and come back a little later to finish.

Step 1

First, you will need to set up an app password. Go to Google App Passwords with your primary Gmail account.

You can pick anything, but I chose “Mail” for the app, and “Custom Name.” For the name, pick something you’ll recognize if you need to reference your app passwords later. I used “Send from user@differentdomain.”

Google App password
Google App password

Copy the password they generate to your clipboard or somewhere temporarily as you’ll need it later.

Step 2

In Gmail, go to the gear at the top right and click on “See all settings.” Click on “Accounts and Import.” Under “Send mail as,” click on “Add another email address.”

Gmail Send mail as
Gmail Send mail as

Step 3

Enter the name and the email address for the second email address that you want to use as an alias. Leave the “Treat as an alias” option checked. Click “Next Step.”

Email address treat as alias
Add another email address you own

Step 4

Leave SMTP Server as Enter your primary Gmail email address in the Username field (not your alias email). Then enter your Google App password that you created earlier. Leave everything else and click “Add Account.”

Gmail SMTP server settings
Gmail SMTP server settings

If your credentials aren’t correct, you’ll most likely see a warning like this:

Authentication failed. Please check your username/password and Less Secure Apps access for

Step 5

A confirmation code will be sent to the email address you want to send mail as (use as an alias). Enter the code and click “Verify.” You can also click on the link in the email to confirm.

Gmail confirmation code
Gmail confirmation code

And that’s it! You now have multiple email addresses in Gmail, and you can send as another email address.

Change From email in Gmail
Change From email in Gmail

You can also change the defaults and the behavior of replies.

Gmail send mail as email addresses
Gmail send mail as email addresses

Another nice feature is that you can set up different default signatures for each email address. This way, when you respond, you can keep separate branding for each email address.

  • Want to start using Google Workspace? Email me for a 10% off promo code for your first year (US only).
  • I also recommend checking out Mimestream. It’s an awesome Gmail app for Mac.


Now you can set up multiple emails in Gmail and manage everything under one inbox. Keep it fast and simple and straightforward; that’s the whole idea. It’s awesome for managing multiple websites, brands, changing domains, etc.

Have any questions about adding Gmail aliases? If so, perhaps I can help. Leave your comments below.

Make sure to also check out my post about the best email forwarding services you can use.

author bio
Brian Jackson

I craft actionable content and develop performance-driven WordPress plugins. Connect on Twitter or subscribe to my newsletter (once a month, no spam).

25 thoughts on “How to properly add an alias to Gmail without errors (send mail as)”

  1. Hi,
    What you have described will be very useful – Thanks.

    Wondering if it solves another problem I have regularly as well.
    My main GSuite account email is @ But due to Linkedin profiles, and other websites / listings etc I often get Google Calendar, Google drive invites sent to my dale AT email account. When I click on the links Google won’t let me accept, says I’m not authorised for GDrive etc because my brwoser is logged in as dale AT GSuite account.

    If I setup these aliases will it know those email invites are really for the same person?


    • Hey Dale,
      Unfortunately, this won’t fix that problem because an alias won’t let you log in to a service. Google states, “Users still need to sign in with their primary email for services like Calendar and Drive.”

  2. Thanks. Like you, I do this every couple of years and forget how to do it inbetween. Unlike you, I haven’t documented it. Cheers.

  3. Hi, Brian, thank you for this tutorial on how to set up aliases in Gmail. I do have one question I wonder if you could answer for me. When I send a calendar invite to the email alias address, I keep getting a “545 5.7.1 spam email rejected” message, even if that invite is coming from another Gmail account. Do you know how I can fix this error?

    Appreciate your time!

  4. FINALLY!!! I have been trying for weeks to get this to work, and this is the only tutorial that explained it all. (It was Step 4, using my PRIMARY address that no one else explained.) Thank you!

  5. At step 4, does it matter which port is selected? If so, can you explain the impact as I selected 465, not 587.
    I really appreciate your explanation and steps. Thank you, Brian!

    • Hey Kim,
      Port 587 is typically the default port for TLS. Basically, it’s more secure. So this is always the recommended port to use. Some also have TLS enabled on port 465, but this can be hit or miss.

  6. Hi Brian THANK YOU so much for these instructions.

    I’ve struggled (and struggled) to set this up. And your notes are the only ones that have helped! You are a star! Really clear language (humanspeak not techspeak) and the screenshots are helpful too. Thank you!

    Kate (New Zealand)


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