What is the Days to Sync Option? How can I Store More Offline Emails on my Device?

Days to Sync means what is the period for which emails are stored on the client for offline usage.

We initially show a period of mails equal to the Days to Sync settings. You can configure it using More (o o o) | Global Settings | Days to sync and select the value you desire.

Note: Once you scroll down we will download another such period.