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I want to use openssl s_client for accessing Gmail POP3S server. I am doing the following:

$ openssl s_client -connect
+OK Gpop ready for requests from <removed: ip> d11pf35377217wam.36
USER <removed:>
+OK send PASS
PASS <removed: password>
+OK Welcome.
+OK 1 messages (2197 bytes)
1 2197
+OK 1 2197

The problem is I am never able to execute the RETR command. It always hangs while "RENEGOTIATING".

What am I missing?

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up vote 3 down vote accepted

I had a similar problem when testing an SSL connection to GMail's SMTP server.

The AUTH and MAIL FROM commands worked fine but when I tried the RCPT TO the server returned the RENEGOTIATING response.

After searching for quite a bit I finally found a site that explained what was going on.

Apparently the uppercase R at the start of the command (RCPT TO for SMTP and RETR for POP3) causes the s_client tool to renegotiate with the server.

The man page for s_client has some info in the "CONNECTED COMMANDS" section.

I managed to get my SMTP test working by using lowercase commands (rcpt to). I've just tried a test with GMail's POP3 server and using retr 1 works well.

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Thanks that helped me a lot Kevin. the retr worked (lower case was correct!) – user67025 Jan 16 '11 at 4:21

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