Plus Addressing Email: Gmail, Outlook, iCloud, Limits

Email plus addressing, also called subaddressing, means adding a plus sign and a tag before the @ in your address. Mail sent to jane+shop@example.com is delivered to jane@example.com, and the tag lets you filter it. It works only where the receiving provider supports it: Gmail, Microsoft 365 work and school accounts, Fastmail, and Proton Mail document it. It doesn’t hide your address, because anyone can delete the tag. For an address that doesn’t contain your real one, CatchNone gives every shop and newsletter its own alias and shows you which one each message reached, on iPhone, iPad, and Mac.

Outlook.com, Hotmail, and iCloud Mail don’t document it, so test those addresses before you rely on them. Provider details below are as of September 25, 2026.

What is plus addressing in email?

The tag is everything between the + and the @. A provider that supports plus addressing ignores the tag when it picks the mailbox, and keeps it in the address so your filters can read it.

RFC 5233 (January 2008) calls this subaddressing and names the + as “one common way” to separate the user from the extra “detail.” It’s an extension to Sieve, a standard language for mail filters, not a rule providers must follow. Only the receiving system decides what the part before the @ means (RFC 5321, §2.3.11), so some mail servers use another separator and some use none.

Google’s help calls these addresses “Gmail aliases.” They aren’t separate addresses: each one contains your real address. This guide calls them plus addresses.

Can you use a plus sign in an email address?

Yes. The + is a standard character before the @ (RFC 5322, §3.2.3). The IETF’s guidance for developers lists user+mailbox@example.com as valid and says programs that check addresses “must simply accept” such characters (RFC 3696). The email field built into web browsers accepts it too (HTML Standard).

Which email providers support plus addressing?

This is what each provider says in its own documentation, as of September 2026. It isn’t a delivery test. Where a provider says nothing, third-party lists contradict each other, so test your address before you rely on it.

Does Gmail plus addressing still work?

Yes. Google’s help still describes it: mail to janedoe+school@gmail.com or janedoe+important.emails@gmail.com goes to janedoe@gmail.com, with a filter per tag. When the “Gmail plus trick” seems to fail, check the site before blaming Gmail: the form may have rejected the +, or the site may have removed the tag. The checklist below covers both.

Does plus addressing work with Outlook?

It depends on which Outlook.

• Microsoft 365 work or school accounts: yes. Microsoft says plus addressing “is enabled by default in Exchange Online.” If no mailbox matches the full address, Exchange tries again without the tag. Tags can’t contain spaces, and users “cannot send emails from plus addresses.”
• Microsoft 365, if tagged mail doesn’t arrive: an admin may have turned it off (Exchange admin center → Settings → Mail flow → Turn off plus addressing for your organization, or Set-OrganizationConfig -DisablePlusAddressInRecipients $true). Older guides that call it off by default are out of date.
• Outlook.com, Hotmail, and Live accounts: Microsoft doesn’t document it. That includes Microsoft 365 Personal and Family plans, which add features to an Outlook.com mailbox. On its Q&A forum, users report tagged mail sorted by a rule in 2024 and some tagged messages missing in August 2026. In the 2026 thread, a Microsoft forum moderator suggested the test to run: send the same message to your plain address and to a tagged one.

Does iCloud support plus addressing?

Apple doesn’t say: its iCloud Mail help doesn’t mention the + or subaddressing. Third-party guides disagree, with some showing it working and others saying mail to name+tag@icloud.com bounces. Test your own address, and a custom-domain address separately if you use one.

Apple documents other ways to get extra addresses, as of September 2026: up to three iCloud Mail aliases; Hide My Email, which needs iCloud+ and creates random addresses that forward to you; and a custom email domain, also with iCloud+.

Does Yahoo Mail support plus addressing?

Yahoo’s help doesn’t mention the +, so test it before you rely on it. Yahoo’s own version uses a hyphen: Yahoo Mail Plus subscribers can create up to 500 disposable addresses in the form nickname-keyword@yahoo.com (as of September 2026), under Settings → Mailboxes (Yahoo Help).

On your own domain

It depends on who handles the domain’s mail. Cloudflare Email Routing supports subaddressing once you switch it on at Compute → Email Service → Email Routing → Settings; user+detail@example.com then matches the rule for user@example.com (Cloudflare Docs). Postfix, a common mail server, has recipient_delimiter empty by default, so plus addressing is off until it’s set (Postfix). The Debian and Ubuntu packages suggest + at install, so many of those servers have it on. A catch-all address goes further: mail to any name at the domain arrives, with no + needed.

How to test your own address

1. From a different account, send a message to your plain address, such as jane@example.com.
2. Send a second message to jane+test1@example.com, and a third to jane+two.parts@example.com to check a tag with a dot in it, as in Google’s own example.
3. Wait a few minutes, then check the inbox and the Spam or Junk folder.
4. If a bounce comes back, keep it: its error text says why the server refused the tagged address.
5. If the plain message arrives and the tagged ones never do, skip tags for signups on that address.

How to filter plus-addressed mail

Gmail

Google’s steps, on a computer:

1. Open Gmail. In the search box at the top, click Show search options.
2. Under To, enter the tagged address, such as yourname+news@gmail.com.
3. Click Create filter.
4. Choose what Gmail should do, such as apply a label or archive, then click Create filter.

Google doesn’t say whether a To filter catches a tagged address that isn’t in the To line, which happens with Bcc and mailing lists. RFC 5233 prefers the envelope (delivery) address for sorting for that reason. In Gmail, search deliveredto:yourname+news@gmail.com (search operators); if it finds the messages, create the filter from that search.

Outlook.com and Outlook on the web

1. At the top of the page, select Settings.
2. Select Mail → Rules, then Add new rule.
3. Name the rule, choose the condition Recipient address includes, and enter yourname+ to catch every tag, or +news@ for one tag only.
4. Choose an action, such as Move to, then select Save.

A condition of yourname@outlook.com won’t match yourname+news@outlook.com, because that text isn’t part of the tagged address. The condition matches any address that contains your text, so plain +news would also catch +newsletters. Microsoft’s rules help notes that the Outlook.com beta applies a new rule only to mail that arrives afterward.

iCloud Mail

On iPhone with iOS 26 or iOS 27 (Apple’s steps):

1. Open Settings, tap your name, then tap iCloud.
2. Below Saved to iCloud, tap Mail, tap iCloud Mail Rules, then tap Add Rule.
3. Enter a name. Use the pop-up menu next to Message to pick a recipient condition, and type the tagged address in the text field.
4. Use the pop-up menu next to Action to choose what happens, then tap the Add button.

On iCloud.com (Apple’s steps), select the Settings button at the top of the Mailboxes list, choose Settings, select Rules in the sidebar, then select the Add button. Enter a name, set the condition below Message and the action below Action, then select Add. A new rule can take up to 15 minutes to apply. Test delivery first, since Apple doesn’t document plus addressing.

Fastmail and Proton Mail

On Fastmail you don’t need a rule: name a folder after the tag, and mail to jane+hiking@example.com lands in a folder called Hiking. On Proton Mail, go to Settings → All settings → Proton Mail → Filters → Custom filters → Add filter (Proton’s steps), and set a condition that matches the tagged recipient.

Why some websites reject a + in your email address

The standards allow the +, so a rejection comes from the site itself:

• A stricter check than the standard. Fastmail says the + is “incorrectly considered invalid by some websites,” although RFC 3696 and the browser’s own email field accept it.
• A deliberate policy. Some sites block or strip tags to stop one person opening several accounts. OWASP’s guidance for developers calls this “not generally recommended.” It says the practice suggests the owner “is either unaware of sub-addressing or wishes to prevent users from identifying them when they leak or sell email addresses.”
• The + turns into a space. In web form data and URL query strings, a + stands for a space (URL Standard). A site that passes your address through a link without encoding it can turn jane+shop@example.com into jane shop@example.com.

Large companies do it too. Microsoft’s account security-info page refuses + addresses as a backup email, which a Microsoft moderator called “a deliberate design choice”, even though Exchange Online delivers them. When a form refuses the tag, use your plain address, a separate alias such as a CatchNone address, or Fastmail’s subdomain addressing, which has no + at all (see how Fastmail’s subdomain addressing works).

Plus addressing not working? A checklist

1. The form refused it: use your plain address or a separate alias (see why some websites reject a +).
2. Nothing arrives: run the side-by-side test and check Spam or Junk. Your provider may not deliver tagged mail.
3. It fails on a work account: a Microsoft 365 admin may have turned it off.
4. Mail arrives without the tag: the site removed it at signup.
5. The filter misses it: use deliveredto: in Gmail, or yourname+ in Outlook.
6. The dots don’t match: dots are ignored only in personal @gmail.com addresses. On work and school accounts, j.smith and jsmith are different.
7. A confirmation link fails: the + may have become a space. Use the plain address, or ask the site’s support.

Is plus addressing safe? Can spammers remove the tag?

It’s safe in the sense that, where your provider supports it, tagged mail still lands in your own inbox. It isn’t private. Spammers can remove the tag, and it takes no skill: your real address is written inside every tagged one. Delete from the + to the @, and what’s left reaches you. Proton’s help says it plainly: “your real address is easy to guess from a plus address.”

Stripping is already written into an ad-industry spec. The Unified ID 2.0 (UID2) spec for advertising identity tells implementers to remove the + and everything after it up to the @, and all dots, from gmail.com addresses before hashing, so janedoe+home@gmail.com becomes janedoe@gmail.com.

So a tag has three limits:

• It doesn’t keep your real address private. Anyone who sees the tagged address sees the plain one.
• It can’t cut anyone off. Filtering a tag to the trash only hides the mail from you, and a sender who strips the tag still reaches your inbox.
• It proves less than it seems. A tag in spam points at one company, or a service it shares data with, not at how the address left it. A tag that’s just the site’s name can be guessed by anyone who has your plain address, and spam without a tag proves nothing, because the tag may have been removed along the way.

Breach lookups need care too. Have I Been Pwned says plus aliasing appears in “approximately only 0.03% of addresses loaded” into it, and it doesn’t treat tagged addresses specially. Search each tagged address you’ve used, not only your plain one. For evidence that holds up better, see how to find out who sold your email address.

The Gmail dot trick, and more addresses in one Gmail account

Gmail ignores dots in personal addresses: john.smith@gmail.com and j.o.h.n.s.m.i.t.h@gmail.com both reach johnsmith@gmail.com. On work and school accounts, dots do change the address. Mail to @googlemail.com reaches the same inbox. Gmail usernames can’t contain a +, which is why the + can work as a separator.

The “infinite Gmail addresses” claim is simple arithmetic: a 10-character username has 9 gaps, each with or without a dot, which gives 512 spellings. They’re all one address, and both Google Ads Customer Match and UID2 tell advertisers to remove the dots. Plus tags are just as unlimited, and every one still contains your address. The dot trick is not a privacy tool.

Dots and tags never give you a separate address. To use real extra addresses in one Gmail account, as of September 2026:

• Forwarding: to read another account’s mail in Gmail, turn on forwarding in that other account. Gmail’s Check mail from other accounts (POP) no longer accepts new users and ends for existing users in January 2027.
• Send mail as: send from up to 99 addresses you already have, under Settings → See all settings → Accounts and import (or Accounts) → Send mail as. It doesn’t create addresses. From January 2027, Gmail drops Send as for third-party addresses such as @yahoo.com or @outlook.com, but not for Gmail addresses you own or Workspace aliases.
• Google Workspace: an admin can add up to 30 aliases per user at no extra cost.

Plus addressing vs a separate alias

A separate alias is an address that doesn’t contain your main one. It can come from an alias app such as CatchNone, a forwarding service, Apple’s Hide My Email, or a domain you own. For the types, see what an email alias is; for the options side by side, see how to hide your email address.

When plus addressing is enough

Plus addressing is free, needs no setup where it’s supported, and does one job well: sorting mail you’re happy to receive. It’s enough when you want newsletters in a label and receipts in a folder, from sites you’d trust with your real address anyway.

It isn’t enough when you want your real address out of a company’s database, when you need to stop one sender without touching the rest, or when the site rejects the +. That’s the job of a separate alias. If you’d rather keep signup mail out of your main mailbox entirely, see what to use as a junk email address.

A separate alias per site with CatchNone

If you want a separate address per site rather than a tag, CatchNone gives you one, in its own app on iPhone, iPad, and Mac. Each alias is its own address, so stripping a tag leaves the alias, not your main email (on your own domain, the domain still shows). Every message is badged with the alias it reached, so a leak or a sold address shows up. Tags still work on top: mail to alias+anything@ is shown under that alias, though on your own domain delivery depends on your provider.

Start with a random address such as abcde-12345@catchnone.com, which needs Premium and no domain, DNS, or mailbox to set up; switch one off and senders get a bounce. Or use a domain you already own: the Free plan includes up to 10 aliases, and Lite and Premium have no limit. The app reads that domain’s mailbox read-only over IMAP or JMAP, directly from your device, so the mail never passes through CatchNone’s servers. The domain’s mail must already reach that mailbox, usually through a catch-all, and the app reads only the inbox, so mail your provider files elsewhere, such as into a Fastmail tag folder, won’t appear. Marking an alias as not in use is only a label, so block the address with a rule at your mail provider. CatchNone is receive-only, so you can’t answer from an alias in it. Download CatchNone, available for iPhone, iPad, and Mac.

FAQ

Is there a limit to Gmail plus addressing?

Google doesn’t publish a limit on the number of tags. The practical limit is length: under RFC 5321, the part before the @, username and tag together, can be at most 64 characters. Gmail usernames are 6 to 30 characters, which leaves at least 34 characters for the + and the tag.

Can I send email from a plus address?

It depends on the provider. Microsoft 365 says plus addresses on work and school accounts are receive-only. Fastmail lets you send from one after you add it under Settings → My email addresses → Add address → Add an address you already own. Proton says that when you reply to mail sent to a plus alias, the plus alias is used as the From address automatically. Gmail doesn’t document sending from a plus address either way, so test it before you count on it.

Is there a plus address generator?

You don’t need one, since any tag works. If you use Bitwarden, its username generator has a Plus Addressed Email type that makes random tags, or, in the browser and desktop apps, tags based on the site, such as alice+github.com@bitwarden.com. For random addresses that don’t contain your real one, see random email address generators.

Should I use a plus address for my bank?

Keep your plain address for banks, government services, and account recovery. Support staff and recovery forms expect the exact address you registered, and a forgotten tag is one more thing to get wrong.