I needed to check an SSL encrypted IMAP connection because a customer wasn’t convinced it was working. I already used Outlook to test the connection, but I needed a telnet like test to show the problem was with the application. Telnet works with SMTP, but for an SSL encrypted IMAP connection I needed the OpenSSL client. These are the steps:
Download and install the latest version of openssl: http://slproweb.com/products/Win32OpenSSL.html
Start CMD and change the directory to:
cd OpenSSL-Win32\bin #Start the client IMAP Session openssl s_client -connect hostname:993 #Login in account mailbox ? LOGIN ACCOUNT PASSWORD #or with a Mailbox Alias ? LOGIN DOMAIN/ACCOUNT/ALIAS PASSWORD #Get folder list "FOLDER" "FILTER" ? LIST "" "*" #Examine Inbox (or any other folder) ? EXAMINE INBOX #Get Message ? FETCH 1 BODY #Logout IMAP Session ? LOGOUT
If you want to know all the other possible commands, I suggest reading RFC 3501: https://tools.ietf.org/html/rfc3501