Preventing spam in Gmail using catch-all and filters

A couple of days ago, most Gmail users were affected by an increase in spam mails getting through Google's spam filters. Our account was also affected with almost 100 spam mails per day. We noticed it were mainly the catch-all addresses being spammed, for example [email protected] We have the mails from multiple addresses forwarded to a single inbox for easier management.

Our method of preventing spam is always using the domain of a website or service we're registering at in our e-mail address itself. For example, say we'd be signing up at possiblespammer.com for whatever reason, we'd use [email protected] so it'd be very easy to block all of their e-mails later, or to find out if they'd sold our e-mail address to a third party.

So, we needed a way to prevent spam to random@ourdo[email protected] addresses, and it turns out the answer is pretty simple: use a Gmail filter. We know that all e-mail which isn't one of our main addresses (f.i. info, sales, ...) and doesn't contain a TLD, which we always use when registering elsewhere, is a spam message. To send these straight to the spam folder, it's possible to create a filter on the "to" field: *@domain.com AND [email protected] AND -(.com OR .net OR .org OR .be OR .nl OR .info OR .gov OR .edu OR .nu)@domain.com.

You could add more TLD's, depending on your location or the types of websites you frequent. For our purposes however, this limited list proves sufficient since most of the websites we register at have .com domains.