Log Message:
Update to Dovecot 2.1.1.  Major changes since 2.0.x:

* Plugins now use UTF-8 mailbox names rather than mUTF-7: acl, autocreate,
  expire, trash, virtual
* auth_username_format default changed to %Lu. If you really want case
  sensitive usernames, set it back to empty.
* Solr full text search backend changed to use mailbox GUIDs instead of mailbox
  names, requiring reindexing everything. solr_old backend can be used with old
  indexes to avoid reindexing, but it doesn't support some newer features.
* Expire plugin: Only go through users listed by userdb iteration.  Delete dict
  rows for nonexistent users, unless expire_keep_nonexistent_users=yes.
* Temporary authentication failures sent to IMAP/POP3 clients now includes the
  server's hostname and timestamp. This makes it easier to find the error
  message from logs.
* dsync was merged into doveadm. There is still "dsync" symlink pointing to
  "doveadm", which you can use the old way for now.  The preferred \ 
ways to run
  dsync are "doveadm sync" (for old "dsync mirror") and \ 
"doveadm backup".

+ imapc (= IMAP client) storage allows using a remote IMAP server to be used as
  storage. This allows using Dovecot as a smart (caching) proxy or using dsync to
  do migration from remote IMAP server.
+ Mailbox indexing via queuing indexer service (required for Lucene)
+ Lucene full text search (FTS) backend rewritten with support for different
  languages
+ FTS finally supports "OR" search operation
+ FTS supports indexing attachments via external programs
+ IMAP FUZZY extension, supported by Lucene and Solr FTS backends
+ IMAP SPECIAL-USE extension to describe mailboxes
+ Mailbox list indexes
+ Statistics tracking via stats service. Exported via doveadm stats.
+ Autocreate plugin creates/subscribes mailboxes physically only when the
  mailbox is opened for the first time. Mailbox listing shows the autocreated
  mailboxes even if they don't physically exist.
+ Password and user databases now support default_fields and override_fields
  settings to specify template defaults/overrides.
+ SCRAM-SHA-1 authentication mechanism by Florian Zeitz
+ LDAP: Allow building passdb/userdb extra fields from multiple LDAP attributes
  by using %{ldap:attributeName} variables in the template.
+ Improved multi-instance support: Track automatically which instances are
  started up and manage the list with doveadm instance commands.  All Dovecot
  commands now support -i <instance_name> parameter to select the instance
  (instead of having to use -c <config path>).  See instance_name setting.
+ auth: Implemented support for Postfix's "TCP map" sockets for user \ 
existence
  lookups.
- listescape plugin works perfectly now

Changes since 2.1.0:

+ dsync: If message with same GUID is saved multiple times in session, copy it
  instead of re-saving.
- acl plugin + autocreated mailboxes crashed when listing mailboxes
- doveadm force-resync: Don't skip autocreated mailboxes (especially INBOX).
- If process runs out of fds, stop listening for new connections only
  temporarily, not permanently (avoids hangs with process_limit=1 services)
- auth: passdb imap crashed for non-login authentication (e.g. smtp).