The University has produced good practice guidance for Academic and Administrative staff: about when to use email and the how to manage Emails as records. Please go to the downloads section of the Registrar's Office web pages: http://www.qub.ac.uk/home/RegistrarsOffice/QUBonly/Downloads/ and click on Guidelines for the Use and Management of Email.
You may also wish to read this document which has tips on message composition and message handling: Draft Guidelines for Effective Email communications [2-page PDF].
Note: You will require Adobe Acrobat Reader on your computer to download pdf files. This software can be downloaded from the Adobe website.