Spam is a security concern because it can contain various phishing and malware attacks. This should be really concerning because the more spam you get the greater chance you will click a link thinking it's legitimate and get hacked.
Once you get on the spam lists, there is nothing you can do to get off of them. It now becomes a question of how important that account is to you?
Hotmail/Outlook is notoriously bad a spam filtering. Contrast that with Gmail or iCloud which have such good spam filtering that I NEVER see spam. "Google says less than 0.1 percent of email in the average Gmail inbox is spam while wanted mail in spam folders is under 0.05 percent." here
So, my recommendation would be to open a Gmail or iCloud account and start to gradually migrate your contacts/mailing lists over to that account.
But if you insist on staying with your current account, there are a few things you can do to mitigate some of that spam:
- Instead of deleting spam, mark it as 'junk'. There should be a button for that. That will better tweak the algorithms.
- There is an Outlook mail setting 'Block attachments, pictures, and links from anyone not in my Safe senders and domains list' checkbox. Then add the senders and domains you trust to this list.
- Don't reply to spam or unsubscribe from spam messages. Don't even look at it as the sender can have a tracker that shows you opened it.
- Never tried a spam plugin myself, but these may be worth a shot: Top Anti-Spam Add-Ins for Outlook
Alternatively, you can forward your mail to Gmail and take advantage of its spam filters. You even have the option of sending and receiving Hotmail from a Gmail account. See here