How I handle spam
If you have an e-mail address, it is a matter of time before it is picked up by spammers. A spam filter is not perfect. Occasionally, spam slips through or legitimate e-mails end up in your spam folder. Here are some ways I try to keep spam to a minimum.
Use different e-mails for different providers
If you fill in your e-mail address in some form, append the name of the company to it. For my dropbox account, I use firstname.lastname@example.org. Then when Dropbox leaks a list of e-mails and I start to receive spam on it, I can immediately see which company leaked my e-mail address and create a filter on it so it goes to the spam folder.
Gmail supports this by using a plus sign in your e-mail address: email@example.com will end up in your account. Sadly, some websites don't accept a plus sign in your e-mail address.
Use a different e-mail address every year
For my normal e-mail, I use an e-mail address with the current year in it: firstname.lastname@example.org. I create filters that does not send anything to the spam folder for the current year, and send all messages to spam for any years before.
Encode e-mail addresses on web pages
I receive about 16.000 spam messages each month, most of which are handled correctly by a spam filter. However, using these methods I can keep the number of errors in the spam filter to a minimum, and be certain that I never miss an e-mail.