PlusAddressing

1 Plus Addressing
- 1.1 Support for Plus-addressing
  - 1.1.1 Web Sites that Accept Plus-addressing, but Mishandle them (and where)
  - 1.1.2 Web Sites that Reject Plus-addressing
2 Comments

Plus AddressingEdit

If email is sent to: "username+foldername@fastmail.fm" it will be delivered to the folder named "foldername" in "username"'s mailbox.

Both the actual folder name, and the folder name used after the + must be all lowercase with no spaces. Eg. Having a folder named 'Stuff' will not work. It must be named 'stuff', and you can send to "youraccount+stuff@fastmail.fm" to have it delivered straight to that folder. If the folder does not exist, the message will be delivered to the inbox.

The Wikipedia article on Email Addresses includes a section on Plus-addressing.

Support for Plus-addressingEdit

The main downside of this approach is that addresses with '+' are considered (incorrectly) by many forms on the internet to be invalid, so entering an address in that form may not always work. Worse, it may be accepted at first, but cause trouble later on, when that address gets mangled -- deleting the + or replacing it with a space or hexadecimal code -- resulting in mismatches, server errors, and botched email delivery. Furthermore, people may find this kind of address hard to remember, because it is still rather rare.

Using SubDomain addressing (foldername@username.fastmail.fm) will avoid these problems, but may result in more vulnerability to domain spamming.

The following sections are working lists of web sites known to not work with subdomain addresses.