Activation Email

So awhile ago wordpress stopped sending activation emails when a user would sign up that contained their password. Instead it would send a link to a new user inside that email that would allow them to set their password.
For whatever reason any time someone signs up on my website they still get that old email with their username and a plaintext password then a link to activate their account.
Is there a way to disable this plain text password?
I don’t mind the whole activation link but having their password in an email in plain text is obviously not a good security feature.

Thanks!

EDIT:
I have attached the email below.
Also is there any way to customize these emails to make them more personal for my users?