If BlueMail is taking up more space than you expected, the Storage usage screen shows exactly what it is holding before you start deleting anything.
Go to Settings | Global Settings | Offline Storage | Storage usage. (That middle entry is named for how your app is set up. It reads Sync where offline storage is switched off, and takes you to the same place. See Offline Storage.)
What the screen shows
At the top, BlueMail reports how much of your device it is responsible for: "App is using 4% of device's storage.", with your own figure in place of the 4.
Below that, the same total is broken down by category, so you can see where the space has gone:
- Emails
- Group Mails
- Photos
- Videos
- Documents
- Stickers & Emoji
- Other
On most accounts it is attachments, photos and videos, rather than message text that accounts for the bulk of it.
Freeing space
Clear Cache on the same screen removes locally stored copies of your mail and re-downloads them as you need them. Nothing is deleted from your provider, so nothing is lost from your mailbox; see Clearing the cache for what to expect afterwards.
For a lasting reduction, keep less mail on the device in the first place: Offline Storage controls how many days of email are kept, and the maximum size of message BlueMail downloads automatically. Lowering either shrinks the Emails figure above on the next sync.
Auto-remove cached media
The bottom of the screen lists how long BlueMail keeps cached media before removing it on its own: Emails after 1 week, Group Mails after 1 day, and Other after 1 month. This is information rather than a setting: the periods are fixed, and the cleanup happens without you doing anything.
If your device itself is short of space rather than BlueMail specifically, see Moving the app to an SD card.
