To fetch arrived messages, store them to the +inbox folder and list up them, use `i'. The list is appended to the bottom of Summary mode for the +inbox folder.
At that time, you may be required to input your password. Please refer to See section Let's get started to know what you should take care when inputing password. If you get sick of inputing your password time to time, please make use of the password-cache mechanism with following configuration.
(setq mew-use-cached-passwd t)
If you use this password-cache mechanism, you can omit password while the password is cached. Since passwords are cached in Emacs, you should take care so that other people cannot touch your computer.
To list up messages in Summary mode or flush it, use `s'. This command asks you to input range. Important ranges for Mew are as follows:
The default range is usually `update'. So, just type `RET' after `s' to get the up-to-date list of the current folder.
You can specify the following ranges though they are not important for Mew.
To go to another folder, type `g'. You can make use of folder name completion with `TAB'. When you move a folder and if Mew considered that its list of messages are old, Mew automatically displays the differences.
Here is a summary for commands up above.