Sending email from telnet

I did it as a fun by sending email from telnet console. Here are the steps:

1. connect to your mail server
telnet [mail.domain.com] 25

Trying xxx.xxx.xxx.xxx...
Connected to mailserver.domain.com.
Escape character is '^]'.
220 mailserver.domain.com ESMTP
2. Enter from address
mail from: validsender@emailaddress.com

250 sender ok

3. Enter to address
rcpt to: validrecepient@emailaddress.com

250 recipient ok

4. Enter message body text
data [hit enter]

subject: [subject line]
[hit enter twice]

[Type your message]

enter "." at a new line

250 ok: Message 4570431 accepted

5. Quit

Resources:

http://www.yuki-onna.co.uk/email/smtp.html - Send email from Telnet