A. A. As with POP3, SMTP messages can also be sent using telnet by
connecting to port 25 on the SMTP server, e.g.
C:\> telnet smtp.savilltech.com 25
Once connected you optionally announce to the server who you are (this
is needed for some SMTP servers)
helo <domain>
e.g. helo savilltech.com
vrfy <user account>
e.g. vrfy john
Once you are verified you can commence to write an e-mail message. The
first command is mail and you specify who it is from, e.g.
mail from:<billg@microsoft.com>
The address has to be in <>. Next you have to specify who
will be receiving the message using rcpt, e.g.
rcpt to:<john@savilltech.com>
The from and to have been completed you can start the body of the
message using the data command. You have to create the header
information in the first lines of the message. Once you have completed the
message enter a '.' on a blank link and the message will be sent. Below is
an example creating a message.
Click here to view image
As you can see I entered a from, date, to and a subject and then entered
the body of the text. Make sure you don't make a mistake as if you
backspace this is enterpreted as a bad character and will be rejected. If
a message is rejected a rejection will be send to the address specified in
the "mail from:<...>" and for this reason you should only
ever put your e-mail address. Although I have used a different address as
a joke you should NEVER do this.
Below is how the message looks when received in Outlook 98:
Click here to view image
The above shows how easy it is to send a message and make it look from a
different address but if you examined the header you would easily see it
was sent from a different mail server and rumble its a fake (and a very
bad one)!
I shall be adding future entries describing how to STOP people sending
mail from your server (as they probably can at the moment).
For full information on SMTP and the commands you can use see
Request For Comments 821.