I haven't had yet time to read all the mails in this list which I skipped in the last few of weeks. I'll try to get to them eventually.
This release contains several new features which haven't been fully tested yet, such as ACLs, master users and Maildir++ quota. If you intend to use them, test them properly first.
This is the first Dovecot release where it's supposed to work well with NFS. Even with indexes being stored in NFS. I was able to test it only with Linux 2.4 kernels as clients though, and it didn't work well in a stress test. It looked like the problem was caused by the kernel caching the data a bit too much. Hopefully I can test soon with 2.6 kernels.
Also note the other changes which might affect you. Especially if you're using Dovecot-LDA remember to upgrade it as well to make sure the default lock_method gets updated in it also.
As for the future, it looks like I'm getting soon paid to develop several features to improve Dovecot's performance (by the company which already paid for ACLs, NFS fixes and many other changes in this release, thanks!).
* Changed the default lock_method back to fcntl. Apparently flock
gives problems with some systems.
* mbox: mailboxes beginning with '.' are now also listed
* Replaced mail_use_modules and mail_modules settings with mail_plugins
and mail_plugin_dir. Now instead of loading all plugins from the
directory, you'll have to give a list of plugins to load. If the
plugin couldn't be loaded, the process exits instead of just
ignoring the problem (this is important with ACL plugin).
+ Added support for "master users" who can log in as other people.
The master username can be given either in authorization ID
string with SASL PLAIN mechanism or by setting
auth_master_user_separator and giving it within the normal username
string.
+ Added ACL plugin with ACL file backend. This however doesn't mean
that there yet exists a proper shared folder support. If master user
logged in as someone else, the ACLs are checked as the master user.
+ Added some Dovecot extensions to checkpassword passdb, see ChangeLog
+ Updated passwd-file format to allow specifying any key=value fields
+ Maildir++ quota support and several quota fixes
+ passdb supporting extra fields: Added "allow_nets" option which takes
a comma separated list of IPs/networks where to allow user to log in.
+ NFS: Handle ESTALE errors the best way we can
+ IMAP now writes to log when client disconnects
+ In shared mailboxes (if dovecot-shared file exists) \Seen flags are
now kept only in index files, so as long as each user has a separate
index file they have separate \Seen flags.
- Fixes to DIGEST-MD5 realm handling so it works with more clients
- BODYSTRUCTURE -> BODY conversion from cache file was broken with
mails containing message/rfc822 parts.
- Fixed several memory leaks
- We could have sent client FETCH notifications about messages before
telling about them with EXISTS
- Compiling fixes for Solaris and some other OSes
- Fixed problem with internal timeout handling code, which caused eg.
outlook-idle workaround to break.
- If /dev/urandom didn't exist, we didn't seed OpenSSL's random number
generator properly. Patch by Vilmos Nebehaj.
- Maildir: Recent flags weren't always immediately removed from mails
when mailbox was opened.
- Several changes to SSL proxying code, hopefully making it work
better.