#telnet mail_server.example.ru 25
root@host1:~# telnet mail_server.example.ru 25
Trying 172.27.16.20...
Connected to mail_server.example.ru.
Escape character is '^]'.
220 mx2.example.com Microsoft ESMTP MAIL Service ready at Fri, 6 Nov 2015 13:01:59 +0300
EHLO example.ru
250-mx2.example.com Hello [89.11.16.183]
250-SIZE 26214400
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-AUTH
250-8BITMIME
250-BINARYMIME
250 CHUNKING
MAIL FROM: info@example.ru
250 2.1.0 Sender OK
RCPT TO: test@gmail.com, shpatserman@gmail.com
250 2.1.5 Recipient OK
DATA
From: info@example.ru
To: test@gmail.com, shpatserman@gmail.com
Subject: Test message1

Text of test message1

.