I sympathize with Microsoft a little about their MSN Hotmail product line as I have formerly worked as an e-mail system administrator/systems administrator and I realize just how quickly e-mail applications and data storage for same becomes the beast that eats and entire network, or at least one that consumes valuable network real estate and resources.
E-mail has always been a network service that has many unseen costs associated with. People never consider the costs of the computing time, network communications and other things associated with delivering -- and at least temporarily storing -- messages that are being sent from one point to another. Most consumers just think it happens by magic. They fail to realize that much like the U.S. Postal Service (or other countries postal services), where you have to pay at least $0.39 to deliver an item (with much of that $0.39 going to the labor costs involved in getting the item from point A to point B), that there is always a cost of doing business when you use e-mail.
Most consumers don't realize this because e-mail is a hidden cost. They pay for it by paying their internet service provider (ISP, for example AOL, Comcast, Verizon, RCN, or any of a bunch of other providers) the monthly fee for their service. That fee covers the costs of the network infrastructure (the servers that are involved in doing everything that customers do, the network cabling, switching, routing and other things involved in running the network for the ISP). A portion of the monthly fees that are paid to the ISP into paying to get e-mail services, so that your e-mail is delivered and so that you will receive e-mail that has been sent to you.
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