If you are getting the error with Horde webmail such as follows
	"User user@domain.com is not authorised for Mail"
	Solution :
	1. Backup horde database
	# cd /var/lib/mysql
	# mysqldump horde > horde.sql
	2. Drop horde database
	# mysqladmin drop horde
	3. Update horde package using command.
	# /usr/local/cpanel/bin/update-horde --force
	4. Now check and repair the horde database.
	# mysqlcheck -r -o horde