E-mail is the abbreviation of Electronic Mail, a communications-based software application for transmitting messages over the Internet as a communications network. Email is becoming the most popular and frequently used application due to the ease of transmitting messages to the recipient even if the distance between the sender and recipient is less than thousands of miles. Most email systems consist of a basic text editor. to write messages, but many allow users to edit messages using the editor of their choice. The message can be sent to the recipient by specifying the recipient's address. Most messages were sent in text and image form, but some audio files can also be sent, but with a limited file size. This application is also capable of sending the same message to multiple users at once. This is called diffusion. The messaging application using the standard email sending protocol, namely Simple Mail Transfer Protocol (SMTP). However, the most commonly used protocol for receiving email is Post Office Protocol v3 (POP3) and Internet Message Access Protocol (IMAP). The receive protocol is used by the email client to retrieve the email message from the domain's email server. Figure 5 below shows the email processing diagram using the specified protocol. Even though the message is not sent on a real-time platform and it is a delay tolerant application, it is still the preferred application because it is the only way to send a letter in the cheapest, fast, flexible and reliable way. Another advantage of email is the ability to store email messages in email mailboxes until the recipient retrieves them and to receive notification to the recipient when new mail is received. Email technology is developing rapidly with the advent of m...... middle of paper ......8 below show the comparison of these two types of FTP.Figure 8. The comparison between FTP active and passive FTPThere are also improvements in FTP technology which are Trivial Fail Transfer Protocol (TFTP) and Secure File Transfer Protocol (SFTP/FTPS). TFTPs are designed for User Datagram Protocol (UDP) with minimal overhead. Each message is an independent UDP datagram. It was still used to boot workstations and network devices. There are two types of transfer modes used in TFTP, namely Netascii for text file transfer and Octet for binary file transfer. While SFTP/FTPS allows clients to request that the FTP session be encrypted using cryptographic tools such as Transport Layer Security (TSL) or Secure Sockets Layer (SSL), so that commands and data contain words password and that sensitive information cannot be transmitted openly over the network..