You're not the only one; spam has increased incredibly over the past six months and it is suggested that the increase in online retail shopping has been the primary cause.
One doesn't have to visit "dodgy" websites to be spammed; innocent activities such as signing on to a newsgroup or forum and buying something from an online retailer - both considered reputable - can open the door to spammers. You can't stop spam and once you are on a spam-list it's almost impossible to get removed from it. Don't ever reply to spam asking to be taken off the list, especially the UNSUBSCRIBE feature; such an activity will simply confirm to the spammer that the email address is active and it will be targetted further.
Things you can do:
1) Newsgroups, forums, subscribed services (such as the SUFC official site) are the prime offenders; who remembers the porn scandal a few years ago when we signed up to the Southend United site; the club denied it was happening yet I used a one-off email address for that sign-up and it attracted an enormous amount of spam. If you can, make up or misspell email addresses (unless the site requires confirmation).
2) Use your webmail or email program spam blocking features. For example, Hotmail has a special quarantine feature that can separate what is considered to be spam from your Inbox. Email programs like Outlook Express have filtering options (Actions > Junk Mail > Junk Mail Options) which done very much the same thing.
3) Use an anti-spam program like
MailWasher which sorts through your mail and separates what it considers to be spam. Such programs can perform this action either at the mail server or at your home computer; the former means that you won't have to waste time waiting for the mail to be downloaded only to find it to be spam.
4) Ask your ISP what services they provide to help block spam; a good ISP should offer something to help reduce spam. If not, consider moving to an ISP that does.
5) Don't respond or forward these emails that ask you to highlight a particular grievance in the world or virus warning to everyone you know EVEN IF you received the email from a trusted (but naive) friend. Over 99% of these virus warnings turn out to be hoaxes; research them before acting and DON'T spread the warning to others unless you are absolutely sure they exist. These types of mails are fantastic to harvest email addresses for the spammers and the fact that so many people fall for them because they think they have come from friends means that the spam list grows by a huge amount each and every day. In short, the spammers are chuckling rather loudly!
6) When forwarding an innocent mail (maybe written by yourself), don't use the CC field to copy in others; use the BCC field as this will shield email addresses from prying eyes. Ask others to do the same.
7) Finally, DON'T submit your email address to opt-out or removal lists; these are hoaxes and you'll simply open your email account to even more spam!