You send a crucial e-mail on a Monday morning, but it doesn't arrive in the client's mailbox, across town, until Thursday afternoon. You lose a pending deal. Exasperating? Yes, but increasingly, as a result of the profound demands placed on e-mail network servers, including spam, spyware and viruses, legitimate e-mail messages that should take seconds to get to the intended recipient may take days, experts tell United Press International's Networking.