Your bank details are in the (unencrypted) email...

I subscribed to the Postcode Lottery, paid for by a direct debit, and had to enter my bank details on the site. I then got an unencrypted email in confirmation, with my bank details (account name, account number and sort code) to check for correctness. Should I ask my bank to give me a new account number? David Gibb

I can't see any point in confirming your details - either the debit works or it doesn't - so there's no reason why they should ever be repeated in an email. (For example, I don't recall Amazon doing this.)

If Postcode Lottery feels it must, then it would be better to encrypt it, but this creates all sorts of support problems. However, you already give your account name, account number and sort code to people whenever you write a cheque, - it's how the system works - so I don't think it's not worth getting too upset about one email.