It will do that if payment method fails repeatedly. i.e. no funds, and the back-up funding source didn't work (if bank transfer, does the direct debit still exist etc?).
It's a signal to check your PayPal, make sure it's good, and then cancel and recreate any automatic payments you may have.
Ah, that was my initial suspicion, but the wording of the email made me think it was something at your end so just wanted to check.
Think it might be a hangover from having my card cancelled, but I think you should still be getting a monthly donation from another email account from me...
I got an email yesterday saying PayPal had suspended my automatic payments?