13.1 Default email client

Emacs allows you to select an e-mail program as the default program it uses when you press C-x m (compose-mail), call report-emacs-bug and so on; see (emacs)Mail Methods.

If you want to use mu4e for this, you can do so by adding the following to your configuration:

(setq mail-user-agent 'mu4e-user-agent)

Similarly, to specify mu4e as your preferred method for reading mail, customize the variable read-mail-command.

(set-variable 'read-mail-command 'mu4e)