# telnet localhost 25 Trying 127.0.0.1... Connected to test-server.test-server (127.0.0.1). Escape character is '^]'. 220 test-server.example-sec.local ESMTP helo localhost 250 test-server.example-sec.local mail from:user01@example.com 250 ok rcpt to:user02@example.com 250 ok 502 unimplemented (#5.5.1) data 354 go ahead From: user01@example.com To: user02@example.com Subject: test this is test. . 250 ok 1184072108 qp 20747 502 unimplemented (#5.5.1) quit 221 test-server.example.local Connection closed by foreign host.
appendix