Free up app storage

Free up Proton Mail storage

Proton Mail keeps encrypted messages in your Proton account. This phone stores a local encrypted cache, search index data, and attachments you decrypted and saved. Clearing cache does not delete mailbox mail. Emptying Trash does.

See how much space Proton Mail is using

iPhone

1. Open the iPhone Settings app.
2. Tap General > iPhone Storage.
3. Tap Proton Mail.

Android

1. Open your phone Settings > Apps.
2. Tap Proton Mail.
3. Tap Storage or Storage and cache.

Attachments

1. Open a message and download an attachment only when you need it.
2. Delete saved copies in Files or Downloads when you are done.

Decrypted attachments you saved are user files on the phone. They are no longer only inside Proton Mail. Clearing the app cache does not remove those files.

Local cache

1. Open Proton Mail > Settings (gear) if the app lists Clear cache or a storage item.
2. Otherwise use Android app storage (below) or reinstall after you save Drafts.

The local cache is for faster open and limited offline reading. It is not a full independent mailbox. Messages stay on Proton when you clear it.

Trash

Deleted messages go to Trash. Emptying Trash permanently deletes them from the Proton account. That is mailbox data, not cache.

Clear Proton Mail cache on Android

1. Open your phone Settings > Apps > Proton Mail.
2. Tap Storage or Storage and cache.
3. Tap Clear cache.

Do not tap Clear storage / Clear data unless you mean to sign out. You will need your Proton password (and mailbox password if you use one). Unsent Drafts on this phone can be lost.

Reinstall the app if storage is still high

If you already cleaned media and Proton Mail still looks huge, a fresh install can clear leftover cache and temp files that are hard to reach by hand.

1. Mail in your Proton account stays. Remember your Proton password. Save Drafts and any decrypted attachments you stored only on this phone.
2. Delete the app from your phone.
3. Restart your phone.
4. Install Proton Mail again from the App Store or Google Play.
5. Sign in and restore from backup if the app offers it.

This often frees a lot of space. You may need to download some media again after restore.

What to do next

After Proton Mail is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.