There are many ways you can do this. (You have the most control if you host your own mail server but I'll assume you don't want to do this. If you do, use tools such as DNSBL and spamassassin to filter the spam server side. In the case of large companies, enterprise level antispam solutions are used and "definitions" similar to antivirus software are updated every 10 minutes to detect the latest spam attacks.) The best place to start is not using your email address to register with websites etc. Use a disposable address instead such as http://www.spambob.com for example Then either use antispam filtering tools provided by your email provider and/or client side tools such as SpamCop / Spambutcher / Mail Washer / POPFile / eXpurgate / Spamihilator / K9 / Spam Interceptor / and the list goes on... You'll find that some of these work better than others but each person tends to a receive different types of spam and thus different products work better for different people. The most severe method of antispam and also the most effective is to block everything except what you whitelist. This method is rarely practiced because it means people must be added by you before they can contact you. This can be semi-automated by sending a reply email to every incoming email to which the sender has to reply a second time to "authenticate" themselves before being whitelisted.