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What are email Plus addresses and how to use them

‘Plus’ email addressing (aka sub-address or disposable email) is a really useful option for managing your incoming messages, if your mail host allow them.

The + trick lets you change the email address given out while still letting the messages to a single mailbox. 

A ‘plus’ email address looks like this  fred+sheep@fredagg.com  – the real address is [email protected] but any address with a + sign and following text will go to the same mailbox.

Here’s just some [email protected] plus addresses.

  • Fred+Lists@
  • Fred+Fence@
  • Fred+Phone@
  • Fred+ATT@
  • Fred+BT@
  • Fred+ConEd@
  • Fred+123@
  • Fred+Taihape@
  • Fred+AnythingYouLike-4_Ahundredormorecharacters@

All the above email addresses (and many more) go to one Inbox for a plus address enabled mailbox.

In other words, a plus address is in this form:

<local address>+<any valid characters>@<domain name>

The sub-address RFC document puts it this way:

:user "+" :detail  "@" :domain

With :detail “–” :user making up the :localpart of the email address.

Strictly speaking, each local part of an email address (to the left of the @ sign) should be a separate mailbox.  In many cases, that’s what happens. 

‘Plus’ addressing is a non-standard feature offered by some mailhosts but not all. There is an Internet standard RFC 5233 for email sub-addressing however it’s optional for mail hosts.

Gmail and G Suite have Plus addresses (e.g.  [email protected] ) .

Outlook.com (formerly Hotmail) added + addressing back in 2013.

Microsoft finally enabled it for the commercial / Microsoft 365 / Exchange Server customers in late 2020. However administrators might have disabled the feature for some organizations.

No setup required

If Plus addressing is available for your mailbox, there’s no other setup required. 

Just start using (giving out) plus address versions of your email address.

Normal email aliases (extra addresses) need to be setup and directed to a mailbox.

We suggest testing your plus address mailbox first, before using them with other people.  Just to make sure the mailhost setup is working properly.

Why use email plus addresses?

Plus addressing lets you create a unique email address for each sender – a person, company or group.

Spam trap

It’s commonly used to identify companies that sell email addresses without permission.  When setting up an account, use a plus address version such as  Fred+CableTV@   or Fred+ThaiRestaurant@     if you start getting unwanted emails, check the To: email address to identify the source.

However, clever spammers are aware of plus addressing and can ‘clean’ their email lists by removing the +…. part, leaving just the main address.  Despite that, it’s worth trying.

Disposable or temporary email address

+ addresses can also make temporary or disposable addresses to remove when you’re finished.

Use the address while necessary.  When you’re finished, setup a rule to delete any more messages from that address.

Public Wifi logins

Lots of public wifi systems have some type of login or address collection, especially airports and other travel destinations.

Peter uses a plus address such as Peter+Wifi@…  for all these logins.  An Outlook rule shunts messages to that sub-address directly to Junk Email folder.

Better email filtering

Sometimes emails arrive that are hard to setup rules for, because their content is inconsistent.  A nerdy example are Dmarc email delivery reports.

Use a plus address like Fred+DMARC@  and it’s easy to make a rule based on the TO address of the incoming email.

Unique email addresses quickly

Use a plus address to share a single mailbox with the different ‘hats’ or roles you have in your life.

If you’re a member of a club, use a plus address to separate messages related to that e.g. Freda+Netball@

Being on the board or managing as a volunteer is similar  Freda+NettyBoard@

Organizations can use a plus address to identify messages from an online feedback page e.g.  +WebForm@ 

Highlight important messages

Many people have multiple email accounts and might send messages to you from any of them.  That makes it harder to manage.

Give that person a plus address like  Fred+fromBruce@  for their contact lists.

How to get ‘Plus’ email addresses, the new feature in Microsoft 365 and Outlook.com
Get the most from Plus addresses in Outlook
A simple check for Plus addressing with your email address
What can you put in your email address?

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