How to customize email/notification to user?

Hello, is possibile to customize the email that wp/q&a sends to new user after he submit a question? He is asked for registration after submitting the question, but he receive only poorly detailed email, like

Username: test
Password: 123456
url website/wp-login.php

Should be helpful adding some useful texts, like "you recently submitted a question on... etc. Is possible?

Moreover: how to customize standard email subject "New answer on"

Thanks