Telnet on Windows 7 doesn’t connect to any server

Shorter answer: Are you sure it’s hanging? Because this doesn’t seem to be a Windows specific issue. Are you expecting a response header? Because I can get a 220 response header when I Telnet to port 25 on smtp.gmail.com.

Longer answer: To me, none of the responses seem abnormal; I do not see these outputs as “hanging.” But rather normal/expected behavior when operating at a raw, building-block level of a network.

For example when I attempt to Telnet to Google.com on port 80 on Mac OS X 10.9.5 (Mavericks) it simply appears to “hang” as well:

telnet www.google.com 80

The response I get is the following:

Trying 216.58.219.196...
Connected to www.google.com.
Escape character is '^]'.

Ditto with attempting to connect to port 465 on Google’s SMTP server as suggested by a commenter:

telnet smtp.gmail.com 465

The response I get is the following:

Trying 74.125.141.109...
Connected to gmail-smtp-msa.l.google.com.
Escape character is '^]'.

But if I attempt to Telnet to port 25 I do get a server response:

telnet smtp.gmail.com 25

And here is what I get:

Trying 74.125.141.109...
Connected to gmail-smtp-msa.l.google.com.
Escape character is '^]'.
220 mx.google.com ESMTP jk10sm23672404vdb.13 - gsmtp

Note the last line with the 220 response banner. I believe that is what you are looking for.

JakeGould

Posted 2015-06-01T22:29:52.933

Reputation: 38 217

1Port 80 is HTTP, a protocol where the client speaks first; the server doesn't send anything until after you send it a request, or it times out which on my test is 4 minutes for google. As long as you don't make typing mistakes, GET / HTTP/1.0 followed by two returns (sent as CRLF CRLF) is a minimal valid request. Port 465 is SMTP-over-SSL/TLS. SSL/TLS is also a client-first protocol, but it uses complicated binary formats that no human could enter from a keyboard or read from a screen. – dave_thompson_085 – 2015-06-01T23:48:12.860

@dave_thompson_085 Not a bad comment. Should maybe be its own answer? – JakeGould – 2015-06-02T01:16:50.373

I dont get any response like you got: Connected to gmail-smtp-msa.l.google.com. – Shlomi002 – 2015-06-02T07:32:34.127

I think the server for www.google.com is not allowing connection on port 23.

Try to do telnet smtp.gmail.com 465 – DiTTiD – 2015-06-01T22:31:55.790

Are you sure that it freezes? For me it looks like nothing happens until I start typing. – gronostaj – 2015-06-01T22:42:50.540

Just run telnet www.google.com 80 – user2196728 – 2015-06-01T23:09:52.623

didnt work: Microsoft Telnet> smtp.gmail.com 465 Connecting To smtp.gmail.com...Could not open connection to the host, on port 25 : Connect failed – Shlomi002 – 2015-06-02T07:28:43.860

You probably have a firewall in the way. Some of the anti-virus products include network interception that may block or terminate connections to certain ports. One I once had would trap any attempt to connect to port 25 and diverted it to a proxying component. Check you don't have such a system installed. – patthoyts – 2015-06-04T12:48:11.860

Telnet on Windows 7 doesn’t connect to any server

Answers