The IMAP protocol workflow consists of the following steps,
- A network connection established between the client and the server.
- A greeting message sent by the server indicating that the client has successfully connected.
- A series of interactions between the client and server.
The interactions consists of strings of lines, i.e. string terminated by a carriage return and a line feed (CRLF or \r\n). Interactions can be both commands (sent by clients) and data (sent by clients and servers). Both the client and the server strictly interact using lines or known length octet streams (8-bit characters) followed by a line.
####Client
An IMAP client issues commands to the server in a CRLF terminated string. The syntax of a command includes a tag, followed by the command and parameters. A tag is an alphanumeric identifier and each client command has a different tag for that session. A tag could be something like but not limited to A1, A2 etc.