Linuxコマンドラインからメール送信

$ telnet localhost smtp
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 octaviadata.com ESMTP Postfix (Ubuntu)
mail from: admin@octaviadata.com
250 2.1.0 Ok
rcpt to: check-auth@verifier.port25.com
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
hey! how are ya!
.
250 2.0.0 Ok: queued as C313FA0ED
quit
221 2.0.0 Bye
Connection closed by foreign host.
$ mail -A /tmp/backup.dump -s "Test Email" test4chkthisbeforeiaccept@outlook.com < /dev/null