[otrs] Importing Tickets via IMAP

Hi, I am currently reviewing OTRS for work. Part of the testing includes having the system import tickets from an IMAP e-mail account which the documentation indicates is possible. However I have been unable to do so following the instructions found in section 7 of the Admin manual. The version of OTRS I am currently running is the one available in the Ubuntu repositories (2.1.7 I believe) is there any extra perl modules that need to be installed? or have I just done something stupid and it should all be working? Thanks Mike Lowen