25 May 2004

Size of individual emails

Email is not the best way to distribute large documents, especially to a number of recipients.

General consensus seems to be that the size of individual emails should be limited: the actual size of the limit is still under discussion. Since it is attachments that increase the size of emails beyond what might be considered "reasonable", discussion is centred around limiting the size of attachments by using the configuration options of email servers.

In some cases (like the uc-chat discussion list for example), no attachments should be permitted. Many commercial ISPs limit attachments to 2MB, or limit the overall size of an individual mailbox to 2 to 20MB. Email larger than the limit, or which would put the size of the mailbox over the overall limit, is bounced back to the sender. Some Government Departments are reportedly limiting email attachments to 4MB.

Whatever limits are put in place, alternative mechanisms for sharing files with colleagues individually or in groups need to be developed and understood by staff. The Division's Public Documents [authentication required] service goes some of the way to providing document sharing with other Divisional staff, but isn't a suitable solution in all cases. Authenticated access to shared network storage is used widely throughout the Division to share files among workgroups, and can be set up on request by the Help Desk, although the administration of these services can be onerous as groups change.

The University Information Management Systems Committee (UIMSC) has established a Working Party on Collaborative Services that includes consideration of these issues among others, and is working on possible solutions.

In the meantime, staff should be reminded that sending "large" files (2MB+) via email is probably not a good idea, and definitely not to a number of recipients. Other ways may be more appropriate: if in doubt contact the cehelpdesk for advice.