1. A system for communicating electronic mail, said electronic mail having a format and identifying a recipient organization which recipient organization receives electronic mail in a recipient's format, said system comprising: at least two exchange means, each exchange means receiving and sending electronic mail in one of a plurality of distinct formats; gateway means associated with each exchange means for converting the electronic mail to the format of the exchange means; and routing means connected to the gateway means for determining the recipient's format from the identity of the recipient organization and routing the electronic mail to one of the exchange means through the gateway means; wherein one of the exchange means can receive mail from a sender organization in a sender format; and wherein the routing means determines the recipient's form at from the identity of the recipient organization and routes the electronic mail through the gateway means to the exchange means which can receive and send electronic mail in the recipient's format.