Mobile Apps: option to store all emails in the account on the device
This would allow me to set a setting in the Mobile App that would tell the app to download all messages and their attachments to my local device.
The mobile device would have every email in the account that is on the server, stored in the app on the local device. This would bring the mobile app to parity with "desktop" email apps that usually do download all emails to the local device
Benefits would include
- being able to search all emails and their contents including attachments locally very fast without having to ask the server to search stuff which is much slower
- all emails and their attachments up until the last sync with the server are available offline to read and view
These days our mobile devices can have large amounts of internal storage. We don't have to treat mobile devices as limited devices that can only talk to the server and cache small amounts of data. My mobile device has 250+ GB of storage, this is plenty more than needed to store very large amounts of email.
As someone who travels to remote locations on a regular basis, this has been a persistent problem The desire to "cache" emails locally for offline use is useful to critical depending on the situation.