strange email from paypal

I have a paypal account which I rarely use. Last Thursday I had an email from them saying my account has been blocked because of some dubious activity. It also said to logon to find out what to do.
Rather stupidly I tried to logon, and only husband's email address came up, so I told him and he said it's a scam!
Very puzzling, I last used it a few weeks ago for a donation to a USA charity and received an email of thanks from them. But it never came out of my bank account. I've rung the bank about it.
Just a warning to others about these internet scams.