E-mail

Application: (outlook etc) Used to create and edit your email message. SMTP/X.400

Presentation: Presents the data to the application layer so it may be read using the mail client. Converts the data back and forth from it's native format.

Session: Establishes a session for delivering and receiving the email once the message has been sent.

Transport: Provides the reliable or unreliable transportation of the data according to the protocol used (tcp, udp, etc.) It also controls themechanisms for providing end-to-end data transport services and for multiplexing the upper-layer application, session establishment, and virtual circuits.

Network: Used to route the message between systems that are not locally attached. (Might not be used if message is sent to a local system and messaging server is local as well)

Data Link: Formats the message into frames and makes sure they are delivered to the right device. Also adds header information with destination and source addressing

Physical: Transmits the frames as bursts of energy, light, sound, etc depending on the media type. Sends and receives the bits that comprise the message itself.