E-mail standard SMTP POP3

1. TCP/IP e-mail Standard

(1) Internet Message format (Internet Message format) ---- defines the header used to encapsulate the e-mail text, including the e-mail address of the sender and recipient.

(2) Simple Mail Transport Protocol (SMTP)-defines the protocol for sending and receiving e-mail.

(3) Post Office Protocol Version 3 (POP3)-defines the protocol for customers to receive e-mail from the server.

2. POP3 is essentially a subset of the SNMP protocol. POP3 is used between the e-mail client and the e-mail server. It does not send emails between the e-mail server. POP3 supports features not available in SNMP, such as the authentication function-identity of a subset of the E-mail client surface and password. The e-mail server determines whether you should be allowed to obtain e-mail.