Gmail Send Mail As a Custom Domain

We rate this tip B tier: it is free, it takes about ten minutes, and each step is on a Google help page today, but it rests on a sign-in method Google itself tells people to avoid. Google's own words on its app passwords page are that they "aren't recommended and are unnecessary in most cases", and the same page says a password change revokes every one of them. So the setup works, and it also breaks without warning the day you change the password of the account you send as.

We think Google keeps app passwords available through early 2027 for accounts with 2-Step Verification, because its Workspace page for printers, scanners and apps still tells administrators to use one with smtp.gmail.com. Confidence: Likely. Check by: Mar 2027.

What George set up on Feb 15, 2024

George Vanous's notes hold this as instructions he wrote for someone else that day: two Google mailboxes on two custom domains, and the wish to read one inbox while sending from either address. The answer in his notes is that Gmail can do it, in four steps. Signed in to the inbox you read, open Settings, then "Accounts and Import", and under "Send mail as" click "Add another email address". Give smtp.gmail.com as the server, the other address as the username, and an app password as the password. His notes give the place to make that password as "Security | 2-Step Verification | App passwords (scroll down to see it)", and then: "In "App name" type "Gmail" then click Create and paste the generated password into Step 2." After that, the notes say, composing a new email offers the second address in the From line.

That is one dated case. What follows is the same setup checked against Google's pages as they read on Nov 10, 2026.

The steps, as Google documents them today

1:08 Google Workspace's own video of Dec 1, 2022 fills in the same server screen: for a Google Workspace account the SMTP server is smtp.gmail.com on port 587, the username is the full address being added, and then comes its password. The video does not say that the password has to be an app password, which is the step people get stuck on.

1. Turn on 2-Step Verification on the account you will send as. Google says app passwords only work on accounts that have it on. The switch is in the Google Account under "Security & sign-in", in the part headed "How you sign in to Google" (Turn on 2-Step Verification).
2. Create the app password in that same account. Google's help now sends you straight to myaccount.google.com/apppasswords rather than describing a menu path, so the scroll George's notes mention is no longer the documented route. Name it anything; he typed "Gmail".
3. In the inbox you read, add the address. Settings, "See all settings", the "Accounts and Import" tab (named "Accounts" on some accounts), "Send mail as", "Add another email address" (Send emails from a different address or alias).
4. Enter the server details. Server smtp.gmail.com; username the full address you are adding; password the app password from step 2. For the port, Google's Workspace page pairs 465 with SSL and 587 with TLS, and the Gmail help page lists the same pairs for other providers.
5. Confirm. Gmail mails a confirmation link to the address you added. Open that mailbox and click it; if it is missing, Gmail's help says to look in Spam.

George's notes do not record a port or the confirmation email, so we cannot say which port he used or whether he was asked to confirm.

When Google will not give you an app password

The app passwords page lists three cases where the option may not appear even with 2-Step Verification on: the account uses security keys only, the account belongs to a work, school or other organization, or it is enrolled in Advanced Protection. The second matters here, because an address on a custom domain is usually an organization account. George's worked on Feb 15, 2024; whether yours shows the option depends on what the domain's administrator allows.

Two more limits from Google's pages. Mail sent through smtp.gmail.com on a Workspace account counts against 2,000 messages a day. And because a new Google password revokes app passwords, "Send mail as" will start failing after a password change until you make a new app password and paste it into the address's "edit info" screen.

The shortcut that did not work for him

An older entry, dated Feb 2, 2021, begins "Could not make this work". The idea was that when two domains sit in one Google account for organizations and one address is an alias of the other, adding the alias under "Send mail as" should ask for no server and no password.

Google still documents an alias route. Its page on alias domains gives the Gmail steps: add the address, tick "Treat as an alias", then follow the confirmation steps. That page does not say whether Gmail asks for a server and password along the way, and the Gmail help page says work or school accounts enter SMTP details. A third page says a newly created alias can take up to 24 hours to take effect. We could not confirm with Google on Nov 10, 2026 why the shortcut failed for George in 2021, and his notes do not say what Gmail showed him. If the alias route asks you for a password, the app password steps above are the fallback that worked for him three years later.

What we checked

All six Google pages linked here were read on Nov 10, 2026. Confirmed: the "Send mail as" menu path, the smtp.gmail.com server, the port and encryption pairs, that 2-Step Verification is required, where app passwords are created, and the three cases where they are not offered. Not confirmed: the old menu path through the 2-Step Verification screen (Google's help no longer describes it), and the reason for the 2021 failure. We did not run the setup ourselves.

Sources

• George Vanous's notes, Feb 15, 2024 and Feb 2, 2021
• Sign in with app passwords, Google Account Help, read Nov 10, 2026
• Turn on 2-Step Verification, Google Account Help, read Nov 10, 2026
• Create and manage app passwords, Google Account (sign-in required), named by Google Account Help on Nov 10, 2026
• Send emails from a different address or alias, Gmail Help, read Nov 10, 2026
• Send email from a printer, scanner, or app, Google Workspace Help, read Nov 10, 2026
• Add a user alias domain or secondary domain, Google Workspace Help, read Nov 10, 2026
• Add or delete an alternate email address (email alias), Google Workspace Help, read Nov 10, 2026