Guidelines for the use of the College-provided email lists
Think twice before sending anything to the lists. If a message for the students is not immediately urgent then maybe it should go out in the JCR/MCR weekly bulletin emails via the JCR Secretary (firstname.lastname@example.org) or the MCR Secretary (email@example.com). Likewise for the Fellows or staff lists; in both of these cases you should consider sending the message to the Registrar (firstname.lastname@example.org) who can include it in the Fellows’ bulletins or the weekly Staff Information Sheet.
If you do have to notify the Fellows or students directly, try to put the whole message in the message body rather than in an attachment. If the formatting is important, use the body to express as much of the attachment content as possible.
If the prospective file for attaching is not generally going to be readable, try to convert it to a format that is. This may be a PDF file, which is still far from ideal; plain text in the message body is still the best solution if possible. The prime example of inappropriate files are Microsoft Word documents, which are neither readable via the Pine email client (the University’s recommended email program), nor reliably readable on the PWF Linux systems, nor easily readable by any Windows or Mac user who hasn't spent money on an appropriate version of Microsoft Office.
If you can put the main bulk of the message in the message body as plain text, do you really need the attachment file? If it's accessible via the Web, a URL (web address) is much better as the message won't require so much downloading time - while not an issue on the University network, for students or Fellows living out with modem connections this can be a big problem.