The most important thing you can do to avoid getting spam email is keep your email private. Don’t post it publicly anywhere.
I recommend having a primary private email address for anything important like emailing friends, family, services, your bank, etc and having a separate email address you use for signing up for newsletters, website offers, rebates, etc.
If your email address is posted publicly on the internet, eventually it will be found and you will start to receive spam.
An easy way to see if your email address is on a website is to do a Google search for “youremailaddress”. It must be in quotes. If Google doesn’t find anything congratulations! I recommend doing the same search using Bing.
If Google does find your email address posted publicly you can contact the site owner and ask to have it removed. Some listing sites will have removal forms. If you can’t find contact information on the web site you will need to do a DNS lookup on their website and contact their provider requesting your private email address is removed from the website. This can be time consuming but it’s worth it in my opinion to reduce the amount of spam you received.