APPLICATION LAYER




  •       SMTP



    One of the common applications run in the application layer is Electronic mail. This requires a protocol for its functioning SMTP (Simple Mail Transfer Protocol). Within the Internet, email is delivered by having the source machine establish a TCP connection to port 25 of the destination machine. Listening to this is an email daemon accepts incoming connections and copies messages from them into the appropriate mailboxes. If a message cannot be delivered, an error report containing the first part of the undeliverable message is returned to the sender.




    SMTP
    PUBLIC KEY ENCRYPTION

    
     HOME