Use Socket to send email 3

Below is a simple command header (this is done after opening the socket), is the test result of my mail to stmp.263.net: HELOlimodou250smtp. 263. netMAILFROM: chatme@263.net250OkRCPTTO: chatme@263.net250OkDATA354Enddatawi

Below is a simple command header (this is done after opening the socket), which is the test result of sending an email to stmp.263.net:
HELO limodou
250 smtp.263.net
Mail from: chatme@263.net
250 OK
Rcpt to: chatme@263.net
250 OK
DATA
354 End data.
To: chatme@263.net
From: chatme@263.net
Subject: test
From: chatme@263.net
Test
.
QUIT
250 OK: queued as C46411C5097E0
This is some simple SMTP knowledge. For more information, see RFC.
RFC 821 defines instructions for receiving/sending emails.
In RFC 822, an email is specified? Capacity format.
Does the RFC 2045-2048 define multimedia mail? Capacity format,
RFC 1113,142-discusses how to enhance the confidentiality of emails.