Type “telnet mail server domain name 25.” Do not enter spaces, just the recipient mail server domain name. For example, the recipient mail server name may be mail.myoffice.com.
Type “HELO your ip address.” Do not enter the spaces, just your address. You can also use your own mail server, but you must enter a correctly formatted IP address or domain server; for example: 192.168.15.2
Type “MAIL FROM:your email address.” Do not enter quotations.
Type “RCPT TO: sender’s email address.” For example, RCPT TO: email@example.com.
Type “Subject: Email Subject” to include an email subject. This step is optional; the email will send without a subject. For example, Subject: Hello foo.
Type your message.
Type “.” This indicates to Telnet that your message is complete.