Test SMTP Host with telnet

telnet mail.contoso.com 25
EHLO test.com
MAIL FROM:Admin@test.com
RCPT TO: User@Domain.Com or RCPT TO:User@Site.Domain.Com notify=success,failure

DATA
Subject: test message
Press Enter two times. You do not receive a response from this command.
Type a period (.) at the next blank line, and then press Enter. You receive the following response:

QUIT
Source: h