The latest version of Dovecot can be downloaded from Softpedia
Dovecot 2.2.8, an open source IMAP and POP3 email server for Linux/UNIX-like systems, written primarily with security in mind, has been released and is now available for download.The Dovecot 2.2.8 server has passed all the IMAP server standard compliancy tests, its indexes are self-optimizing, and it is admin-friendly. It also features a very efficient authentication system, and it supports migrations from other IMAP and POP3 servers.
This latest version arrived pretty fast after the previous and integrates even more changes. According to the release notes, the mail cache lookups now work for the mail that's being saved, the mail cache works for recently cached data, and the client no longer gets disconnected.
Check out the changelog for a complete list of fixes. Download Dovecot 2.2.8 right now from Softpedia.