1. A method comprising: encrypting in a client device flow control information associated with an electronic message, the flow control information including identities of a sender and an intended recipient, the encryption using an encryption key unique to the intended recipient; transmitting a separately encrypted electronic message with the encrypted flow control information from a client device associated with the sender to a group mailbox server associated with the intended recipient, wherein the group mailbox server receives a plurality of electronic messages for a plurality of different recipients including the intended recipient, transmitting to the intended recipient, independently of the transmission of the electronic message, a first decryption key for decrypting the flow control information associated with an electronic message; and downloading, by the intended recipient, at least the flow control information of a plurality of messages from said group mailbox server associated with the intended recipient, wherein the messages and encrypted flow control information are retrievable by all members associated with said group mailbox server; applying, by the recipient, the first decryption key to the plurality of electronic messages received by the group e-mail server to identify the electronic messages for the intended recipient at least in part according to whether at least a part of the electronic message or the encrypted flow control information can be decrypted by the decryption key; and using information from the portion of the electronic message that can be decrypted by the first decryption key to obtain a second decryption key from a key server, the second decryption key used by the recipient of the message to decrypt at least a second portion of the electronic message.