Editing Post Office Protocol (section)

==Session example==
The following POP3 session dialog is an example in RFC 1939:<ref>RFC 1939, page 19 (https://datatracker.ietf.org/doc/rfc1939/)</ref>

 <span style="color:blue;font-face=italic">S: <wait for connection on TCP port 110></span>
 C: <open connection>
 <span style="color:blue;">S:    +OK POP3 server ready <1896.697170952@dbc.mtview.ca.us></span>
 C:    APOP mrose c4c9334bac560ecc979e58001b3e22fb
 <span style="color:blue;">S:    +OK mrose's maildrop has 2 messages (320 octets)</span>
 C:    STAT
 <span style="color:blue;">S:    +OK 2 320</span>
 C:    LIST
 <span style="color:blue;">S:    +OK 2 messages (320 octets)</span>
 <span style="color:blue;">S:    1 120</span>
 <span style="color:blue;">S:    2 200</span>
 <span style="color:blue;">S:    .</span>
 C:    RETR 1
 <span style="color:blue;">S:    +OK 120 octets</span>
 <span style="color:blue;">S:    <the POP3 server sends message 1></span>
 <span style="color:blue;">S:    .</span>
 C:    DELE 1
 <span style="color:blue;">S:    +OK message 1 deleted</span>
 C:    RETR 2
 <span style="color:blue;">S:    +OK 200 octets</span>
 <span style="color:blue;">S:    <the POP3 server sends message 2></span>
 <span style="color:blue;">S:    .</span>
 C:    DELE 2
 <span style="color:blue;">S:    +OK message 2 deleted</span>
 C:    QUIT
 <span style="color:blue;">S:    +OK dewey POP3 server signing off (maildrop empty)</span>
 C: <close connection>
 <span style="color:blue;">S: <wait for next connection></span>

POP3 servers without the optional APOP command expect the client to log in with the USER and PASS commands:

 C:    USER mrose
 <span style="color:blue;">S:    +OK User accepted</span>
 C:    PASS tanstaaf
 <span style="color:blue;">S:    +OK Pass accepted</span>