My Mailbox Is Full: How to Fix Gmail Storage (2026)

Q: What should I delete first to free the most space?

Large attachments. Search larger_than:10M in Gmail and a few dozen messages will usually account for more space than thousands of ordinary emails. After that, empty Trash and Spam, then clear old promotional mail in bulk.

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When Google says your mailbox is full, your account has used all 15 GB it gets for free, and that 15 GB is shared between Gmail, Google Drive and Google Photos. The consequence is worse than a cluttered inbox: new mail stops arriving and the people writing to you get a delivery failure notice. Nothing you already have is deleted, so your mail is safe, but the account stops working until you free space.

Everything below is Gmail on the web. Two things to do in order: find out which of the three services is responsible, then clear the space where it actually is.

First, check what's using the space

Don't start deleting email. Plenty of people spend an afternoon on their inbox when the real problem was a phone backing up video to Google Photos. Open your Google account's storage page at one.google.com/storage and you'll see the 15 GB split three ways, with the largest consumer named.

If Drive or Photos is the bulk of it, that's where to work, and clearing email won't help much. If Gmail is the one eating the space, keep reading.

Clear the big attachments first

This is where the gigabytes are. A few dozen messages with video, slide decks or photo attachments will usually outweigh thousands of ordinary emails. Search Gmail for:

larger_than:10M

Sort through what comes back, delete what you don't need, and repeat with larger_than:5M if you need more room. Our guide to arranging Gmail by size covers the full set of queries, including how to combine size with a date range so you're only looking at old material.

Empty Trash and Spam, or nothing changes

This is the step people miss, and it's the reason the storage bar doesn't move after a big delete. Deleted mail goes to Trash and keeps using space there. Gmail empties Trash automatically after 30 days, which is 30 days you don't have if your mail is bouncing right now.

Open Trash in the left sidebar (click More to expand it) and choose Empty Trash now.
Do the same in Spam. Spam counts against your quota too, and on a neglected account it can hold years of mail.

The space comes back within a few minutes of emptying, though the storage display can lag behind by a little.

Then clear the bulk mail

With the attachments and Trash handled, the next largest block is usually years of promotional email. The efficient way to remove it is by search rather than by scrolling:

Search something like category:promotions older_than:1y.
Tick the checkbox above the message list, then click the link offering to select all conversations that match this search.
Delete, confirm, then empty Trash again.

Check the first page of results before you confirm, and exclude any sender you want to keep with -from:store@example.com. The full version of this technique is in how to mass delete emails in Gmail, and getting rid of promotions in Gmail covers that tab specifically.

One more place to look. Everything you ever archived is still in your account and still counted, and there's no folder showing it, which is why it goes unnoticed for years. Deleting archived messages in Gmail has the search that isolates it, and reading all your email in Gmail explains the All Mail view it lives in.

Why it filled up

Storage runs out for one of two reasons: a few enormous files, or a steady drip from senders you never read. The first is a one-off cleanup. The second refills whatever you clear.

When someone runs their first scan with our extension, it finds about 15 subscription senders on average. Shops they bought one thing from, apps they tried once, newsletters they meant to read. Each one sends a few messages a month, with images, forever. Clearing the backlog without leaving those lists means doing this again next year with a bigger number.

Our data also shows roughly a third of unsubscribe attempts hit senders with no working unsubscribe mechanism at all: no one-click endpoint, no working link, nothing. We report those failures per sender instead of hiding them, because for those senders blocking is the fallback that works. The free options built into Gmail are covered in how to unsubscribe from emails.

Find the senders filling your storage, leave their lists, and clear their backlog in the same pass. The scan is free, read-only, and takes about a minute.

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Buying storage instead

Google sells more space through Google One, and if your 15 GB is full of things you genuinely want to keep, paying for a larger plan is a reasonable answer. Check the current tiers and prices on Google's own pricing page rather than taking a number from an article. Worth knowing before you subscribe: a paid plan raises the ceiling without changing the inflow, so if subscription mail is what filled the account, it will fill the new allowance too.

Common questions

What happens when my Gmail mailbox is full?

You stop receiving mail. Messages sent to you bounce back to the sender with a delivery failure, and you cannot send either. Nothing already in the account is deleted, so the mail you have is safe, but the account stops working as a mailbox until you free space.

Why is my mailbox full when I barely have any emails?

The 15 GB is shared between Gmail, Google Drive and Google Photos, so the space is often used by files and photos rather than mail. Check the storage manager in your Google account before deleting any email, because it shows which of the three is actually responsible.