Checking imap/exchange connectivity

Sometimes, you want to troubleshoot network connectivity and access to an imap server, like Exchange or other ones. Of course you can use telnet, like:

• telnet <your exchange server> <port>

The tcp port could be 143 or 993 if it has been configured to only accept secure connections (SSL).

In some cases, even by telnet, it does not work which does not mean that there is a connectivity problem. In this case, you can use opensslto test your connection to your imap server. Note that you can install openssl even on Windows, just go here. On linux, openssl you be available.

So, use this string to connect to your imap server over a secure channel:

• openssl s_client -connect <server>:<port> -crlf

The port could be 993. Just don’t forget the option -crlf. Without this, you will not be able to use Return after entering a command at the prompt.

Then, when the connection is made, you can use this commands:

• ? LOGIN username password
• ? SELECT Inbox
• ? LOGOUT

Use ‘? <command>‘ (The ? sign, a space, and the command) or this will not work. The username is the username you have on your domain/exchange/imap server (the @domainname should not be needed here).

Ref : link1, link2, link3

Filed under: Uncategorized, 993, exchange, imap server, openssl, ssl, telnet, test connectivity