Mailbox full: back up emails and free up space

In short: If your mailbox is full, back up what you want to keep first and delete afterwards. With Gmail, email, Drive and Photos share up to 15 GB, according to Google. Once the limit is reached, mail can no longer arrive. The safe order: find large attachments, archive locally, check the archive is complete, then delete on the server and empty the trash.

What happens when your mailbox is full?

With Gmail, the storage of the whole Google account counts: Gmail, Google Drive and Google Photos share up to 15 GB, according to Google (as of October 2026). Once the limit is reached, you can no longer send or receive email, and messages sent to you are returned to the sender. Signing in still works.

Other providers have their own limits, which you find in your customer account. The steps below apply in the same way there, the numbers do not.

Important if you stay over the limit: Google says content may be removed if the quota has been exceeded for more than two years. Before that, you are notified at least three months ahead by email and in Google products. A local copy is especially valuable then.

How do I find out what is taking up the space?

Usually it is a few large messages with attachments, not the bulk of the text. Google gives the search has:attachment larger:10M in the Gmail search box as an example. It shows messages with attachments over 10 MB. Also check the "Storage" area in Google Drive: it lists files by size, and often more sits there than in the mailbox.

How do I back up emails before deleting them?

Do not delete anything you might need later (invoices, contracts, correspondence). Here is how:

1. Connect the account in Mail Archive. The app detects server settings for Gmail, Outlook.com, GMX, Web.de and other providers with IMAP or POP3 automatically.
2. Choose folders and a start date. To move only older mail out, pick the period accordingly. The app saves attachments as separate files.
3. Let it archive. By default the app only reads; your messages stay unchanged with your provider.
4. Spot-check. Open a few messages with attachments in the archive and run a full-text search for a term you know. Search works across all accounts, offline too.
5. Back up the archive itself, for example to a second drive or in your computer's backup. A local copy does not replace a backup.

How do I free up space afterwards?

Once you have checked that the archive is complete, there are two ways:

• Delete by hand with your provider. Delete the large messages you have already archived. Then empty the trash and spam folders: according to Google this is the fastest way, since items in those folders still count towards the limit until they are permanently deleted.
• Mark archived messages as deleted in Mail Archive. This is an option you have to switch on explicitly; it is off by default. The app then marks archived messages as deleted on the server and frees up space in the mailbox. Switch it on only after the spot check.

After deleting, Google updates the storage display after a short while. With very many deleted files it can take about 48 to 72 hours, according to Google.

Should I just buy more storage instead?

That is one option. Google offers subscriptions through Google One. The catch: it keeps costing money, and the mailbox keeps filling. A local archive is a one-time payment and moves the old mail out for good. Which fits better depends on whether you need old mail regularly and how fast your mailbox grows.

How do I prevent it next time?

• Move mail out once a year: everything older than a year goes into the archive and out of the mailbox.
• Newsletters and notifications: unsubscribe or delete automatically with a filter.
• Do not leave attachments in the mail: Mail Archive saves them as separate files, so you no longer need them in the mailbox.
• Business mail: invoices and contracts have retention periods. Read How long do you have to keep emails? and ask your tax advisor before deleting anything.

More guides: Save Gmail emails locally and Gmail account locked: how to get your emails back.

Which version fits?

To try it, the free version is enough (1 account, 20 emails, no time limit). For a full mailbox you need more: Pro (€14.99, one-time) archives unlimited emails from up to 6 accounts. Pro Plus (€39.99, one-time) allows 8 accounts and adds the e-invoice overview and AI access; it is available for Mac, with Windows to follow. Business (€129.99, one-time) is meant for companies and clubs with many accounts and includes batch export and automatic cleanup after the retention period. All differences are on the pricing page; the app is available for Mac and Windows.

Mail Archive is not a certified archive system and does not replace tax or legal advice.

Frequently asked questions

What do I do when Gmail storage is full?

Search for large attachments, archive what matters locally, then delete and empty trash and spam. Alternatively buy more storage with Google One.

Can I delete emails and still keep them?

Yes, if you archive them locally first and have checked the archive. After that you can delete them with your provider; the copy stays readable and searchable on your computer.

Does Mail Archive delete my emails?

No, unless you explicitly switch on the option to mark archived messages as deleted. By default the app only reads.

Why is storage still full after deleting?

Deleted items keep counting until trash and spam are emptied. Google also updates the display with a delay, about 48 to 72 hours for many files.

Google information as of October 2026, based on Google's official help pages on Gmail storage and the Google Account storage limit. Google may change limits and processes.