Let me point you to the answer, I've got on @programmers, that answers my own, very similar question.
In this question, I was asking, if the fact that my bank is using the same password (as I use for login) for password-protecting PDFs generated at each end of month, means that they're storing this password plain-text in database.
In general, I was advised, that this doesn't have to mean that. In my opinion, this is a good supplemental lecture to all the answers, you've got. Maybe the same thing happens in your situation? Maybe, the fact that you got your password clearly printed in your e-mail, doesn't actually means, that it is stored plain-text in database.
Please, threat this answer as addition. I'm not security specialist, I'm only following answers, that someone else has wrote for me.