Namespaces

Dovecot supports fully configurable namespaces. Their original and primary purpose is to provide Namespace IMAP extension (RFC 2342) support, which allows giving IMAP clients hints about where to locate mailboxes and whether they're private, shared or public. Unfortunately most IMAP clients don't support this extension.

Dovecot namespaces can be used for several other purposes too:

Providing backwards compatibility when switching from another IMAP server
Provides support for public shared mailboxes
Allows having mails in multiple different locations with possibly different formats

See namespace sections in example configuration file for more information.

Backwards Compatibility

When switching from UW-IMAP and you don't want to give users full access to filesystem, you can create hidden namespaces which allow users to access their mails using their existing namespace settings in clients.

# default namespace
namespace private {
  separator = /
  prefix =
  inbox = yes
}
# for backwards compatibility:
namespace private {
  separator = /
  prefix = mail/
  hidden = yes
}
namespace private {
  separator = /
  prefix = ~/mail/
  hidden = yes
}
namespace private {
  separator = /
  prefix = ~%u/mail/
  hidden = yes
}

For Courier-IMAP compatibility, use:

namespace private {
  separator = .
  prefix = INBOX.
  inbox = yes
}

Shared Mailboxes

See SharedMailboxes.

Multiple Mailbox Locations

INBOX in /var/mail/username, maildir in ~/Maildir, other mboxes in ~/mail under #mbox/ namespace:

namespace private {
  separator = /
  inbox = yes
  hidden = yes
  prefix = "#mbox/"
  location = mbox:~/mail:INBOX=/var/mail/%u
}
namespace private {
  separator = /
  prefix =
  location = maildir:~/Maildir
}

Without the hidden = yes setting in the first namespace, clients see the "#mbox" namespace as a non-selectable mailbox named "#mbox" and having child mailboxes (ie. like a directory).