Hi there,
Back in the live-steam age of the internet, my work issued me with an email address, and put it online. Oh dear.
Five years on, I was getting perhaps fifty pieces of spam per day. An easy job to delete them. About five years after that I was getting four to five thousand spam emails a week. Using Outlook most of these were easily filtered straight to the bin, but it was annoying, so I changed my email address at work. Result - no spam for the first few years, and now only four or five a day.
I would recommend a regular change of address - but do remember to tell the people you'd want to hear from that you've done it!
Barring domains is a bit sledge-hammery, but it can work well, as long as you're sure there aren't legitimate people on that domain who you might want to hear from. Blocking a sender is less effective - as I mentioned, spammers spoof "sent from" addresses all the time, so it's an easy job for them to send you multiple copies from all sorts of apparent addresses.
Andy