The File Transfer Protocol (FTP)It is a standard network protocol used for the transfer of computer files between a client and a server on a computer network.Simple Mail Transfer Protocol (SMTP)SMTP stands for Simple Mail Transfer Protocol.SMTP is used when an email is delivered from an email client, such as Outlook Express, to an email server or when an email is delivered from one email server to another.SMTP uses port 25.Simple Network Management Protocol (SNMP)It is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior.Therefore SMTP protocol is used for transforming electronic mail messages from one machine to another