Open Radar

 
Summary:
Add three email accounts to an iOS device. Sync several (and optionally hundred) MB of mail to the device for local storage, View the Storage summary and discover that Mail usage is not shown

Steps to Reproduce:
1. Add three email accounts to an iOS device. 
2. Gmail, iCloud, IMAP in my case - but any three will do as long as there is content in the inbox of each
3. Open Mail and Sync several hundred MB of mail to the device for local storage. In my case, after downloading mail on all accounts, including attachments in each account. My device has 11.7 GB available and 16.4 GB Used.
4. Open the settings app
5. Tap General
6. Tap Usage
7. Wait for the Storage initial items to be shown. Look for Mail in the list
8. Tap **Show all Apps** since Mail isn't listed as a top user of storage. (Numbers at 334 MB is listed)
9. Optionally - scroll up and down and up looking for Mail in vain. I know it's a blue icon and I know it's taking up more than 100 MB of storage space on my hardware.
10. Give up and file a radar

Expected Results:
Mail usage should show as a line item in the storage. Even if there is no data in the mobile Mail.app - it should show that on the list of storage similar to other apps.


Actual Results:
iOS does not expose how much space downloaded mail occupies on the storage. With attachments and multiple mail accounts - this can be a large portion of the storage space on a device and not doing the work to calculate how much space Mail occupies seems an odd design choice.

Regression:
unknown if this is a regression or not

Notes:

Even if I go into Mail settings and turn off mail for each account, go back to mail and see the "Welcome to Mail" screen to encourage me to set up my first Mail account on the device, returning to the Storage / Usage / General screen, returning to the storage settings still shows 11.7 GB Available and 16.4 GB Used. Are these values somehow cached? Does Mail app not actually delete downloaded mails when you turn off Mail for an account (and leave it inactive in settings) to save space for photos and videos while on vacation?