Cyrus imap server uses MODIFIED UTF-7 encoding for folder names in older versions.
The new configuration property 'com.openexchange.mail.filter.useUTF7FolderEncodin g' has to be set to 'true' if a cyrus imap server is used whose version is lower than 2.3.11.
Otherwise moving mails with the 'fileinto' command will not work for mail folders with special characters in their names.

The default value will be 'false'.
Changing this value will not affect existing filter rules.
Broken filter rules because of special characters in mail folders will not start working after changing this property. They have to be updated manually by their user to start working correctly.