I am having the same issue, suddenly getting 15-20 junk emails a day. I've had my acct for over 15 years as well and haven't changed any settings. I'm relieved to know I'm not the only one, but still pretty mad that this is happening.
I've been blocking them as they come in, but also went on DMAChoice.com and signed up to opt-out of marketing email. Although, they say it doesn't stop 100% of these emails, only those that use e-MPS, and it will take 2 months for the marketing emails to decrease in my inbox. There has to be a better solution!!! :(