Gmail has a well-known hidden feature that helps emails reach your inbox: If you have a dot in your email address, the email service ignores it, which means that emails sent to your.user.name@gmail.com will go to the same inbox as yourusername@gmail.com.

But a similar feature that can be even more useful in sorting through your inbox often flies under the radar, as The Next Web informs us. You see, Gmail will ignore anything after a plus sign in an email address. In other words, if you send an email to yourname+@gmail.com, it will still go to your email inbox. Ditto yourname+onlineshopping@gmail.com.

Google has previously suggested that you could use the plus sign to filter your inbox with specific keywords, like using yourname+bank@gmail.com for all your bank logins. Then you would set up a filter to put all emails to that address in one folder so that Gmail would automatically tag all emails to yourname+bank@gmail.com as “finance” or whatever other filter name you choose. You can already do this by setting up filters for specific email senders, but this way, if you had multiple banks, you would only have to set up one filter.

As The Next Web points out, it’s also a useful way to see who’s giving out your email address. If you only use your.name+uselesslogins@gmail.com for websites that you’re not a particularly active user of, you’d then know if they were giving out your email if you started receiving messages sent to your.name+uselesslogins@gmail.com from other sites and businesses. Or you could use your.name+donations when you’re giving money to charity, so that you can filter and delete the endless requests for more donations you’ll get from then on out.

Sounds like a pretty big plus, huh?

[h/t The Next Web]