Only if the send you your old password. If they reset your password, they can send you the plaintext first, then hash the password and store it in the database.
No. The problem is that email isn't encrypted on the backend. Sending a plain text password means every server between the website's SMTP server and your email provider's SMTP server can see the password.
a) Work once. If you click on a password reset link and it says it's already been used, you know something is up, v.s. someone using the plaintext password to log in before you and you are non the wiser.
b) Expire. Lot's of people won't bother changing the password that was given to them, so anyone who comes across a plaintext password in the email at a later date would be able to log in.
Temporary plaintext passwords are rare; I don't think I've ever seen one. If you've got as far as temporary plaintext passwords, I'd argue it's a better UX to provide a simple link instead of forcing them to copy and paste something.
