What is a Gmail alias?

The term covers two different things. One is a variation on the Gmail address you already have, such as you+shop@gmail.com or the same address written with dots, which still delivers to your inbox because it is your address. The other is a genuinely separate address on a different domain that forwards into Gmail and that Gmail can be configured to send from. Only the second keeps your real address out of it.

How do I send email from an alias in Gmail?

In Gmail on a desktop browser, open Settings, then See all settings, then the Accounts and Import tab. Under Send mail as, click Add another email address, enter the name and the alias, and click Next Step. Fill in the SMTP server hostname from your alias provider, port 587, and the username and password the provider issued, with the TLS option selected. Gmail then emails a confirmation code to the alias, which you paste back into the window that is still open.

Do I need SMTP set up before I can reply from an alias?

Usually not. A forwarding service that rewrites the reply address on each message it forwards means pressing Reply in your normal mail app sends the answer back through the service, which delivers it onward as the alias, with nothing configured. Reply All is the exception, because the other recipients on the thread are ordinary addresses in your mail app and get their copies direct from your real address. SMTP setup is for starting a new conversation as the alias.

Is Gmail plus-addressing a real alias?

It is real and free, and widely supported, but it is a convention rather than a standard and it is a filing tool more than a privacy one. Everything between the plus sign and the at sign can be removed in one line of code, the address contains your base address in plain sight, and there is no way to switch a plus address off, so unwanted mail still arrives and can only be filtered after delivery.

Why has Gmail's confirmation code not arrived?

Most often the alias is not forwarding to your inbox yet, so send it a test message from another address before changing anything else. If forwarding does work, check the spam folder and check that the alias has not been disabled. The confirmation email also contains a link that verifies the address without the code, which helps if the code window has already closed.

Gmail Aliases: Send From Any Alias in Gmail

Q: Which port and security setting should I use in Gmail's Send mail as?

Port 587 with the TLS option, or port 465 with SSL. Do not mix them, because a mismatched pair is the most common cause of the setup failing. Port 587 is reserved for message submission by RFC 6409 and is what most providers document. Port 25 is for server-to-server delivery, is blocked on many networks, and should not be used here.

Two different things get called a Gmail alias. What plus-addressing can and cannot do, and the exact Send As steps for sending from a real one.

You are on a signup form and it wants an email address. You would rather not hand over the one that has fifteen years of banking, tax and family mail behind it. So you search for a Gmail alias, and you get two different answers that are both called the same thing, and only one of them does what you had in mind.

This guide covers both, in order of cost. First the options Gmail gives you free, which are better than their reputation for some jobs and useless for others. Then the one most people are actually after: a genuinely separate address that lands in Gmail and that Gmail can send from, with the exact menu path and the exact fields.

One thing up front, because it saves people an evening of fiddling. Sending a new message as an alias and replying as an alias are different jobs. The second usually needs no setup at all. If replying is all you need, you can skip the walkthrough, and there is a section below explaining why.

The two things people mean by "Gmail alias"

The first meaning is a variation on the Gmail address you already have. One account, one inbox, one password, and you hand out you+shop@gmail.com instead of you@gmail.com. Nothing is created. It is your address wearing a hat, and Gmail delivers it because it was always yours.

The second meaning is a separate address on a different domain, something like shop.k4x2@example.com, which forwards into your Gmail and which you can also send from. Nothing about it points back at your Gmail address. This is the one people mean when they say they want the shop not to know who they are.

There is a third thing that shares the name and clutters the search results. In Google Workspace, an administrator can add alternate addresses to a user account on a domain the organisation owns. That is a Workspace feature, not a personal gmail.com one, so if the instructions you found send you to an admin console, they were not written for you.

Gmail's own options first: plus-addressing and dots, which are free

If your address is you@gmail.com, then you+anything@gmail.com already reaches you. Nothing to switch on, nothing to pay, no account to create. This is a standard rather than a Gmail quirk: it is subaddressing, described in RFC 5233, and several other providers support it too.

The useful part is that the text after the plus sign survives into the message, so Gmail can filter on it. Build a filter on To: you+newsletters@gmail.com, attach a label, and your signups sort themselves without you touching a rule again.

It also does a modest job of leak detection. If mail addressed to you+kitchenshop@gmail.com arrives from a company that is not the kitchen shop, you have learned something about what the kitchen shop did with your address. That is not nothing, and it cost you nothing.

The dots trick is the smaller sibling. Google ignores full stops in gmail.com addresses, so j.o.hnsmith@gmail.com and johnsmith@gmail.com are the same mailbox, and Google documents this itself. It applies to gmail.com only. On a Workspace account with your own domain, dots do change the address.

What the free options are genuinely good for:

Sorting your own mail. One address per newsletter, one filter, done.
Spotting whether a company passed your address on, as long as whoever bought it kept the plus text intact.
Getting a per-service address in the time it takes to type it, with nothing to install and nobody to pay.
Signing up to something you expect to be harmless, where all you want is tidiness.
Trying the habit of a different address per service before you spend money on it.

If that is your problem, stop reading here. You are done, it works today, and paying for anything would be waste. The rest of this guide is about the jobs plus-addressing cannot do.

Where those stop: trivially stripped, and they reveal your base address

Deleting everything between the plus sign and the at sign is one line of code in any language. Brokers do it on purpose. Ordinary developers do it by accident, while normalising addresses to stop people opening duplicate accounts. Either way, the moment your address is written into somebody's list, you+shop@gmail.com can quietly become you@gmail.com and stay that way.

The deeper problem is that a plus address announces the address it is meant to be hiding. you+bank@gmail.com contains you@gmail.com in plain sight, so anyone who reads it, human or script, has your real address without doing any work. Dots are the same: strip them and you have the canonical address.

Then there is the off switch, or the absence of one. There is no way to make you+shop@gmail.com stop working. Once it is on a spam list you can filter the mail after Gmail has accepted it, but it still arrives, it still costs you attention, and every delivery confirms the address is live.

There is practical friction too. The plus sign is a legal character in an email address, and plenty of signup forms and call-centre systems reject it anyway. You will discover which ones on the form that matters, usually while standing in a shop.

So the honest summary: plus-addressing and dots are filing tools that leak a little privacy as a side effect. If you want the address itself to be separable from you, and switchable off, you need an address that was never yours to begin with.

A real alias in Gmail: the Send As walkthrough, step by step

The setup assumed here is that you have an address somewhere else, either at a forwarding service or on a domain you own, and mail to it already reaches your Gmail inbox. What is missing is the other direction, so that Gmail can put that address in the From line.

Test the forwarding before you touch any settings. Send the alias a message from your phone and check it lands. If it does not, the confirmation email later in this process will not land either, and you will spend an hour blaming the SMTP fields.

Have four things to hand. Your alias provider publishes them, usually under a heading like SMTP or sending settings.

The outgoing server hostname. Every provider publishes its own, and it is never your own domain unless you run the mail server yourself.
The port. It is 587 in almost every case.
The username. Usually the full alias address, occasionally a separate username the provider generates for you.
The password. An SMTP password issued by the provider for sending. Not your Gmail password.

Now the path, with the labels as they stand at the time of writing. Google reorganises this menu every couple of years, so if a label has drifted, look for the nearest equivalent rather than assuming the feature has gone.

Open Gmail in a desktop browser. The Gmail apps for Android and iOS cannot add a sending address, though they can send from one once it exists.
Click the gear icon at the top right, then See all settings.
Open the Accounts and Import tab. On some accounts it is labelled just Accounts.
Find the Send mail as section and click Add another email address.
A small window opens. Name is what recipients see beside the address. Email address is the alias itself.
Leave Treat as an alias ticked. Google's guidance is that the box belongs ticked when messages sent to the other address arrive in this inbox, which is exactly what a forwarded alias does. Untick it only if you read that address somewhere else entirely. Click Next Step.
Fill the SMTP fields. SMTP Server is the hostname from your provider, Port is 587, and Username and Password are the SMTP credentials the provider issued. Choose the option labelled something like Secured connection using TLS, which is the one that pairs with port 587. Click Add Account.
Gmail emails a confirmation code to the alias. Because the alias forwards to you, it arrives in this same inbox. Paste the code into the window that is still open, or click the link in the message, which does the same job.
Compose a new message. The From field is now a dropdown with both addresses in it.

One more setting is worth thirty seconds. Still under Send mail as there is a choice called When replying to a message, offering either reply from the same address the message was sent to, or always reply from your default address. The first is almost always what you want, because it stops you answering an alias thread from your personal address by accident.

Note what is happening technically. Gmail hands the message to your provider's server, so it is that provider's domain doing the sending and the signing. That is why the message passes authentication checks rather than looking like a forgery, and it is also why the provider's sending limits apply to whatever you send this way.

Replying needs none of this

Most walkthroughs imply you must do all of the above before you can answer a single email. For any forwarding service built properly that is wrong, and it puts people off the whole idea before they start.

Here is the mechanism. When the service forwards a message to you, it rewrites the address your mail app will answer to, so your reply goes back through the service instead of straight to the sender. The service then sends it onward as the alias. RFC 5322 defines the header field that does this, and mail clients obey it, because that is what it is for.

The consequence is that you press Reply in Gmail, on the web or on your phone, exactly as you always do, and the person at the other end sees the alias. Nothing is configured. It works the same in Apple Mail and Outlook, because it is not a Gmail feature at all.

So the Send As walkthrough above is for one job: starting a new conversation as the alias, where there is no message to reply to. If you only ever answer mail that arrives, you can skip it entirely.

The honest exception applies across the whole category rather than to any one product. Reply All includes the other people on the thread, and their addresses are ordinary ones sitting in your mail app, so those copies go direct from your real address. In a group thread where you need to stay masked, reply to the sender only.

It also depends on the service doing the rewriting in the first place. Plain forwarding that you set up yourself, a forwarding rule on another mailbox for instance, rewrites nothing, so replies to forwarded mail go out from your real address.

Test it once and stop wondering. Ask a friend to email the alias, reply from Gmail, and ask them which address the reply came from.

Troubleshooting: codes, ports, passwords and spam

The confirmation code never arrives. The usual cause is that the alias is not forwarding yet, so check that first by sending it a message from another address. If it does forward, look in the spam folder, and check the alias has not been switched off or expired. If the code window has already closed, the email also contains a link that verifies the address on its own.

Authentication failed, or Gmail sits there after Add Account. Almost always the port and the security option are mismatched. Use 587 with TLS, or 465 with SSL, and do not cross them. Port 587 is reserved for message submission by RFC 6409, which is why nearly every provider expects it. Port 25 is for server-to-server delivery, is blocked on many home and office networks, and is not a submission port.

The password is rejected even though you are sure it is right. The field wants the SMTP password your alias provider issued for sending. That is not your Gmail password, and it is not the password you use to log in to the provider's website. If the outgoing server happens to be Google's own, because you are adding a second Google account, then 2-Step Verification changes the rules: you need an app password, and Google only issues those to accounts that have 2-Step Verification turned on.

A certificate or TLS error. Usually the hostname is misspelt, or it is your own domain rather than the provider's. Your domain has no certificate for mail; the provider's server does. Use the hostname in the provider's documentation even when your aliases sit on a domain you own.

Mail sent from the alias lands in spam. First work out whether it happens for everyone or just one recipient. A brand new sending address with no history is treated harshly for a while, and a reply inside an existing thread often gets through when a cold first message does not. Beyond that, deliverability is the provider's responsibility, because their server is doing the sending: they publish the SPF record and sign with DKIM. Sending one message through a checker such as mail-tester.com will tell you whether those are in place.

The signup form refuses the address outright. Some sites reject well-known alias and disposable domains at registration. That is a domain reputation problem rather than a Gmail one, and the usual fix is an alias on a domain you own, because it looks like any other mailbox.

The alias does not appear in the From field on your phone. Confirm it is verified on the desktop first, under Send mail as, then close and reopen the mobile app. The dropdown only offers addresses that have finished verification.