I've often wondered what the total size per year is for corporate email legal disclaimers, both bandwidth and residing on disk, world-wide. Personal signatures

I've often wondered what the total size per year is for corporate email legal disclaimers, both bandwidth and residing on disk, world-wide. Personal signatures would be an interesting stat as well. Does Exchange (or any other mail servers) have some sort of de-duplication process for intra-message text like this? The wasted space has to be enormous in aggregate, but maybe compared to headers, attachments, etc. it doesn't end up being that big of a deal, especially for a single organization.