title: How to test smtp email with DOS, not telnet?
body: <p>I know how to test smtp email using telnet. But I think because telnet uses "its own channel" to reach smtp server, it doesn't necessarily mean the normal smtp communication on port 25 would work. (Please correct me if this is not true)</p>
  
  <p>Basically the client has encountered with an issue : [ERROR] Access to default session denied during a test from application to reach smtp server. From the same server, telnet to send an email just works...</p>
  
  <p>So I've got no other choice but to figure out why I am getting this sort of error. Done my research only to find out lots and lots of command-line email applications, no good in this case as it is the client's environment that I've got little control on what to install.</p>
  
  <p>So I think the last resort would be using simple DOS commands? Please advise if there is even a better way. Many thanks in advance.</p>