Runbox supports subaddressing, which is also often called plus addressing. This allows you to add a + in your email address followed by what is called a tag. An example is shown below for the account

You don’t need to set this up as an alias in your account, it just works, and email sent to any address in this format is delivered to the mailbox of the account username that appears before the + (i.e. in our example). The example above could be used for online shopping perhaps, but you can have any tag you choose for any purpose you want.

This kind of addressing useful because you can:

  • just make up the addresses as you go along without the need to set it up in your Runbox account
  • use a plus address for anything where you might want to identify the place where you used your email address
  • use a different tag for each online website you sign up for so that if one leaks your address you know which one it is
  • create a filter to delete email to that particular plus address if it starts receiving spam
  • filter email to specific folders based on the plus addressing

Of course, you can also use email aliases that you set up in your account under Account > Aliases for all of the above too, but the plus addressing has the advantage that you don’t have to set it up before you use it, and you can have as many as you like.

Plus addressing works with aliases as well as your main account email address.