The scan engine has been improved. The internal mail scanner now supports multipart/partial messages, and support for decoding non-standard mail files was greatly enhanced. clamav-milter by default uses libclamav and scans emails itself without the use of clamd. libclamav can now extract RFC2397 encoded data within HTML documents, block zip archives with modified information in local header, and scan HQX files. PE file structure rebuilding from compressed executables was improved too.
An important note to clamdwatch users: please upgrade to the latest version (it is under contrib/) as soon as possible.