The rest of the steps are the same no matter which operating system you're using. Type HELO yourdomain.com where yourdomain.com is the domain name from which you send e-mail. Note that there is only one L in HELO. Press ↵ Enter.  You should receive a reply like "250 mail.server.com Hello yourdomain.com pleased to meet you." If you receive no response or an error message, try EHLO instead of HELO. Some servers prefer one to the other. Type mail from:  you@server.com, using your own e-mail address. Make sure there is a space after the mail from:. Press ↵ Enter.   You should receive message that says something similar to "250 Sender OK.” If you see an error, double-check that you’re using an e-mail address with the same domain as the server. Your server may not allow you to send a message with your yahoo.com address, for example. Type rcpt to: friend@friendsdomain.com, where the e-mail address is that of your actual recipient. Press ↵ Enter.   You should see a message that says something along the lines of "250 OK – MAIL FROM you@yourdomain.com ". If you receive an error, the e-mail address you are trying to send a message to may be blocked. You’ll need to enter a few commands to format and send the message.   Type data and press ↵ Enter. On the next line, type subject:  test and press ↵ Enter twice. Replace “test” with your desired subject. Type your message.  When you’re done, press ↵ Enter. Type a single . to end the message, then press ↵ Enter. You should see a message that confirms your message was accepted or queued. This message varies across servers. If you see any sort of error message, write it down and contact your e-mail provider. Press ↵ Enter.

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Write a summary of the previous text in Vietnamese:
Chào máy chủ. Nhập thông tin người gửi vào phần “tiêu đề”. Nhập địa chỉ email người nhận vào. Soạn thư. Nhập quit để thoát telnet.