Most organisations have some sort of email quota, ours seems to be about 2GB, and I’m currently approaching it.
Considering this must be an issue for many people there seems to be a lack of simple programmes that help users identify what is using their email quota. Deleting a few email with very large attachments can be far more productive than trying to delete hundreds of normal emails, each only a few kilobytes in size.
http://www.broobles.com/imapsize/ is something I haven’t needed to use for a few years.
It is a useful application that helps identify large mail folders, and large emails within them. In an ideal world it wouldn’t require users to enter their IMAP details to use it, but that’s not really the fault of the application itself.
How well imapsize works depends partly on the features supported by the IMAP server in question, but this is a great little utility which I think more people should probably be using when trying to cut down on how much space their email account is using.