Applications
Computer Mail (SMTP)
- Uses FTP but only one TCP connection for commands and data
- open a TCP connection to the recipient host SMTP server
- send official host name as identification (recipient checks against IP source addresses)
- Recipient replies with official host name; check against IP
- After verifying all recipients in this manner transfer the message to each host
- if more messages to the same host repeat the above steps
- reverse the roles do all steps
- end connection.