By Gordon Gottsegen for WIRED.
MARKING AN EMAIL AS "Read" doesn't mean it's gone. It's still sitting there, taking up precious storage space. It's a good habit to delete emails once you are done with them, but if it's already too late and your Gmail is nearing its capacity, listen up.
Google gives its users 15 GB of free account storage. This may be more than enough for some people, but it's important to keep in mind that these 15 GB are shared by your Gmail, Google Photos, and Google Drive. That means that if you are an extensive Google Photo Uploader, you'll be significantly taking away from the capacity of your inbox.
To win the battle, though, you have to arm yourself with knowledge: You need to know how much space you've filled. To find this, log into Google Drive, then on the main page run your cursor over the bottom-left corner where it says "Upgrade storage." This will give you a breakdown of how much storage you are using per service. If you click on the "Upgrade storage" button, you'll be taken to another page where you can buy more for a monthly fee. Extra storage ranges from 100 GB to 30 TB, costing $1.99/month to $299.99/month, respectively. In case you were wondering, a standard academic research library takes up only 2 TB of space, so odds are you won't need that much.
Unless you want to start paying, you can get more space by deleting the stuff you don't need. It's time to de-clutter and gain a little Gmail wiggle room.
Delete From Your Drive and Photos
Because space is shared, deleting from your Google Drive and Google Photos will give you room for your Gmail. In Google Drive, move your cursor back over Upgrade Storage and when you see the pop-up, click on the blue "i" icon next to Google Drive. This will take you to a quota page where you can see how much space you are using per item.
If you use Google Photos a lot, you'll want to head into your settings, and make sure the upload size is selected as "High quality" instead of "Original." When you choose the latter option, you'll be able to upload images in their full resolution, but it will count against your storage quota. By choosing the "High quality" option, Google gives you unlimited storage.
Take Advantage of the Categories
The Gmail web browser automatically separates your emails into default categories. To see what those categories are, and what each one consists of, click the gear button in the top right corner, then Settings > Inbox. A good idea is to delete all of the emails under the "Promotions" category. This category has all of those product newsletters that you probably didn't realize you were subscribed to. These emails also tend to be heavy with images, which takes up space. It's a good idea to get rid of all promotional emails after you've read them--but before you delete everything, check Settings to make sure no important emails are being filed in that category. Then go to Inbox > Promotions and head to the select menu in the top left, and click "All." When you select all, a yellow pop-up message will appear above the category tabs stating that only the messages on this page are selected, it then prompts you to select all messages in that category. Do that and then hit the trash icon at the top. RIP, Groupon emails.
Block and Unsubscribe
Now that you've gotten rid of all those promotional emails, it's time to make sure you stop receiving them. If you use the Gmail Android app, you can unsubscribe from mailing lists straight from the email body.
If you aren't an Android user, you'll have to unsubscribe by navigating through each email, and their corresponding mailing list webpage. This is pretty tedious, but luckily there is a quicker fix: Gmail has a feature that allows you to block senders, and you can do this to any annoying mailing list (or annoying person). Just open up an email from the sender you want to block, then click the drop-down menu next to the reply arrow, and choose "Block Sender." This will automatically move the emails you receive from these senders to the spam folder. The spam folder clears emails that are older than 30 days, so you may want to delete all the emails on your own for the immediate gratification.
Gchat, Notes, and More
Gmail stores a lot of things you may have not realized. That Gchat you had two years ago? Still there. Those things you wrote in your iPhone Notes app? Saved forever. With that said, you'll probably want to navigate the left-hand column under the "compose" button. Click the "More" option to show a list of things that Gmail stores. Some of these things (like "Notes" and "Chats") you may have no desire to save, so delete liberally.
Search for Giant Emails
A lot of little emails add up over time, but there may be some behemoths lurking in your inbox without your knowledge. To find the culprits, you'll need nothing more than your trusty search bar.
Hit the search bar, then click the downward facing triangle on the right side to show search options. When you click the arrow, a drop-down menu will appear that looks like this:
The best part about the search options is that it allows you to search for emails with attachments and emails over a certain size. Using these features, I was able to find two emails that were over 20 MB, and quickly got rid of them. Do this and you'll see an immediate difference.
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