Hello,
If you are using a public mail server you should contact the provider or increase the spam level threshold to reduce spam. If you are using your own server, you may want to consider implementing an RBL like SORBS.net, adding anti-spam software to your server or both.
Many AV clients also have spam filtering capabilities greater than those that may be provided by your email provider so maybe check ESET or other AV software with SPAM filtering to reduce your inbox clutter.
This is a complex problem unfortunately so you are going to have to spend some time and research. A quick fix would be to change your e-mail address and make sure you do not post your email on the Internet, use it to apply to freeware, giveaways and questionable services and don't partake in chain emails.
-Miguel Fra
https://www.falconitservices.com