What Email Filters Are, and Why You Should Use Them

Ever gotten repeating emails from a website that you just can't get rid of? If you use Gmail, would you like to be able to prevent emails from a certain address from ever being marked as important? Would you like to store work orders or other requests in a separate folder automatically? Email filters give you the ability to take control of what emails get presented in your inbox and how they're displayed to you there.

I'm going to show you how to set up a filter in Gmail, since that's what I use (and because it has one of the more powerful and useful filter systems out there), but virtually every email client provides a filter of some sort.

Filters are essentially just a search that's automatically applied to your incoming mail, so they're pretty easy to understand. Here's how to set one up:

1. Locate the filter settings in your Preferences or Settings. In Gmail, it's under the Filters tab in your settings (in the new layout, you have to click the gear icon in the upper-right-hand corner to get to settings).
2. Determine criteria that match the email you want to filter out. See below for suggestions on what you might want to filter. You can typically search the subject, sender, receiver (different depending on whether it was sent only to you or to a mailing list), or body text. You can also frequently check for whether a message has an attachment.
3. Type the criteria and test the search on emails you already have. If your email client is any good, you'll be able to see what messages you already have that match the filter. If it looks like it's going to work, you can set the filter.

No ideas on what you might want to filter? Here are a few ideas:

• The most obvious is when a website is sending you spam that you can't get rid of. For instance, I somehow wound up on a software development list that I did not sign up to be on, and no matter how I changed my preferences, I couldn't seem to get off of it. To correct the problem, I simply went into my email settings and filtered on the search subject:([supertux OR [meta) (this matches the prefix that comes before the subject in every message from the list) and set the action to "skip inbox" and "delete." Now I never see the messages anymore.
• If you use Gmail, you may not know that you can use a +anything after your email address. For instance, emails sent to both john.smith@gmail.com and john.smith+spam@gmail.com land in John Smith's inbox. Since you can filter on what address an email was sent to, you can take advantage of this to help filter spam and track the source of it when signing up for less-than-kosher websites. You can also use it to specify that certain email is important. For instance, you could opt to have email sent to john.smith+bob-urgent@gmail.com automatically starred and flagged as important if Bob's messages are always important.
• If you're on a mailing list or two, it might be nice to have email from the list kept in a separate folder if you don't always want to look at it with the rest of your email. (If you use Gmail, you can also label it without removing it from the inbox if you just want to be able to look through the archives more easily later.)

In Gmail, there's another handy way to create a filter: build a search from the ordinary search box, then click the little arrow next to the search box and choose "create a filter from this search".