What you see below is spam e-mail arriving at a rate of about 25 per minute, or a new one every couple of seconds.
Obviously this is disconcerting, and it will usually stop within a couple of hours.
You Probably Had an Account Hacked
If this has happened to you, the most likely reason is that one of your online financial accounts was breached, and someone either changed your password, or made a charge.
Check All of Your Accounts
Maybe it was Paypal, or Amazon, or Ebay, some obscure credit card, etc. and the hacker is bury you in emails, trying to force you to miss either your “you have been charged…” notification, or perhaps it’s a change of email or change of password notice.
Make sure your passwords still work, and make sure there’s no rogue transactions. Honestly, the best thing you can do in this scenario, EVEN IF YOUR TRANSACTION HISTORY LOOKS OKAY, is to change your passwords for all of your accounts to something more secure.