IMAP connection theory The first thing any client needs to do is to make a connection to the remote imap server on a specific port. These ports can vary, but default port for plaintext imap service is 143, and for encrypted (SSL/TLS) imap service is default port 993. You can use for plaintext imap connection a telnet utility, or for encrypted imap service you can use openssl s_client command.
What is a cipher suite? Cipher suites decide how secure, compatible and fast your HTTPS website is. A cipher suite is a set of information that helps determine how your web server will communicate secure data over HTTPS. A web server uses certain protocols and algorithms to determine how it will secure your web traffic. These are the ingredients of a secure connection. A cipher suite is essentially a list of those ingredients.