telnet smtp communication

root@Linux:/> telnet mail.somedomain.com 25
Trying 10.10.10.10...
Connected to mail.somedomain.com.
Escape character is '^]'. 
220 mail.somedomain.com ESMTP Exim 4.04 Wed, 13 Nov 2002 16:27:42 -0700
HELO mail.someotherdomain.com
250  mail.somedomain.com Hello mail.someotherdomain.com [10.10.10.20]
MAIL FROM:<Jim@someotherdomain.com >
250 OK
RCPT TO:<Joe@somedomain.com>
250 OK
DATA
354 Enter message, ending with "." on a line by itself
Subject:Test Message 
This is a test message.
.
250 OK: queued as 18C6vd0005Ey-00
QUIT
221 mailhub.somedomain.com closing connection
Connection closed by foreign host