New user receive activate email

Hello,
after a new user registrate on my website he receive an activation email as follows:

<Username: Test Password: test1234 Please click this link to activate yout account. act-link>

I’m not sure which programm send this mail. Could it be a theme function php problem?. But I can’t find anything about that problem, that there is the user’s password. (only Username and the link)

Also I can’t find the settings for this mail. Where can I change the content of this mail?

If the new user change his password in his profile, he receive an confirmation email without information about the new password. And the language is now in german.

Furthermore there is another problem. The email receiver will not see the template I choose.

I try the plugin easy wp smtp email – but it doesn’t work.

I despair on that problem. Anybody an idea? Need help!

Thanks.
alex