Listescape plugin
=================

The Listescape plugin allows users to use characters in mailboxes names that
would otherwise be illegal (due to the underlying mailbox storage), for
example:

 * Maildir++ layout disallows using the '.' character (unless LAYOUT=fs is
   used), since it's used internally as the folder hierarchy separator.
 * The '~' character at the beginning of the mailbox name is disallowed,
   because of the possibility that it gets expanded to user's home directory.
 * The '/' character is disallowed on POSIX systems.

The Listescape plugin allows you to use all of these characters, as long as the
virtual separator (i.e. what is set by the separator= setting and used as such
by the IMAP protocol) is changed to something else, which means that the plugin
does *not* make it possible to use the virtual separator in folder names.

The characters are escaped to the mailbox name as \NN hex codes.

So what would be a good hierarchy separator to use?

 * '.' and '/' are very commonly used and should work everywhere
 * '\' is used by Exchange, and should also work everywhere (when specifying
   this in the separator= setting it must be quoted, so one sets separator =
   "\\")
 * '^' is used internally by Thunderbird and causes some trouble with it
 * others?

Examples
--------

Allow '.' characters with Maildir++ layout when virtual hierarchy separator is
changed to '/' (it could be anything else except '.' itself):

---%<-------------------------------------------------------------------------
mail_plugins = $mail_plugins listescape

namespace private {
  separator = /
  inbox = yes
}

plugin {
  # The default escape character is '\', but you can change it.
  # Note that even here the expansion of % takes place, thus you need to
  # use "%%" if you want to have the % sign as the escape character.
  #listescape_char = "\\"
}
---%<-------------------------------------------------------------------------

Allow both '.' and '/' characters when virtual hierarchy separator is changed
to '$'. The '$' has to be quoted to avoid variable expansion.:

---%<-------------------------------------------------------------------------
mail_plugins = $mail_plugins listescape

namespace private {
  separator = "$"
  inbox = yes
}
---%<-------------------------------------------------------------------------

(This file was created from the wiki on 2019-06-19 12:42)