A service module incorporated within the network infrastructure intercepts packets communicated between a client and a server to determine whether the connection corresponds to an email service. If so, the service module breaks the connection by terminating the connection with the client at the service module and opening a separate connection between the service module and the server. Packets communicated between the client and the server may then be redirected to an email compression application that monitors messages communicated between the client and the server and processes the messages in accordance with the state of the email session. For messages corresponding to connection establishment, user authentication and other protocol-specific messages, for example, the email compression application may be configured to forward the messages to the originally intended destination. Messages corresponding to an email message data, however, are buffered within the email compression application. Once the entire message has been received, the email compression application may strip the message headers and any protocol-specific data, compress the data and attach new message headers corresponding to the compressed email message. The compressed and reformatted email message is then reinserted into the data stream for transmission to the intended destination. Because compression may occur between the server and client, compression may be performed without requiring special processing by the server before email messages are sent. Furthermore, because the email messages may be compressed in a format that can be readily decompressed using decompression libraries incorporated within the operating system of client devices, such as the CAB format or GZIP format, the client may decompress received email messages utilizing software already incorporated within the operating system of the client device, without requiring download or installation of special decompression software and/or coordination of compression/decompression of email messages with the server or sending party.