Why isn't Telnet enabled by default in Windows 7?

When I pinged my mailserver from the command prompt using:

telnet mail.mydomain.com 25

I got the error Telnet is not a recognized command. I looked for a workaround and then found that Telnet was unchecked by default in Windows. Once i checked it, it started working.

Solution 1:

TELNET communicates with the peer (telnet server) in clear text.
This is a security hazard compared to say the SSH connect. To this end, the telnet client on windows is disabled by default. This often comes as a surprise and many sites describe the steps to get it working,
you seem to have found them already :)

For normal purposes, it would be a better option to use SSH (PuTTY or freeSSHd if you want to connect to a Windows machine).

Solution 2:

When wanting to query in clear text an SMTP server, to my knowledge, there isn't any simpler way to do it than Telnet. [SSH can't be used for this]

In this case I advise you to enable telnet or to use something like SMTPDiag.