Conceptually, it is not possible for a user to receive the initial password in any other way than via an e-mail automatically generated by the system.
The background to this is to ensure that the password does not fall into the wrong hands. In addition, the user's email address will be verified as correct – if it is incorrect (e.g. due to a typo) the user would not receive the initial password by email, and the user account would not be created with the wrong email address.
Of course, this only applies if email is active as the login method. (When using other authentication methods (e.g. Active Directory, RADIUS) there is no initial password.)