I am new in IOS system. I used Outlook for my email base in Windows 10, where data base can be stored at certain folder. Thus, I can back up the folder to external harddisk from time to time.
Now, I moved to iPad Pro, trying to used Outlook, too. I can’t find where this email data base is stored by Outlook in local drive.
iPad, iOS 10
Unlike Microsoft Windows and other computers with which you may be familiar, iOS/iPadOS does not fully expose its filesystem to the User. As such, you cannot necessarily manage your iPad or its data using techniques that you use elsewhere.
iOS/iPadOS uses a sandboxed security architecture, where each installed App maintains its own private file-space and data - this often only being accessible from within the App that owns it.
Mail can be accessed using either a specific third-party App, or using the iPad's native Mail App. Different Mail Providers might use different mail-protocols - such as IMAP, POP3 or something else. That said, it is common for Mail Providers to keep all your mail saved on their Mail Server until deleted by you - and a local copy of your mailbox messages being downloaded to your local device. As such, the need to back-up your mail messages is already taken care of by the Mail Provider.
POP3 Mailboxes, where this is your only option, can be problematic. This very old mail protocol allows two principal modes of operation - these being Download and delete (keeping mail only on the client device), or Download and leave a copy on the server (which leaves mail accessible from the server until deleted by a client device). Assuming that you are not using POP3 to access mail, you can dismiss this protocol from further consideration. You should note that the majority of Mail Providers offering POP3 also offer more flexible alternatives that eliminate the inflexibility of POP3 mail.
Returning to device backups...
Given that the sandboxed security architecture prevents Apps from accessing other Apps private data, your options to backup iPad data are native:
How to back up your iPhone, iPad, and iPod touch - Apple Support
While App data can be included within backups, this data cannot be selectively restored. Restoring an iCloud or iTunes backup will replace all device data with that of the backup.
Unlike Microsoft Windows and other computers with which you may be familiar, iOS/iPadOS does not fully expose its filesystem to the User. As such, you cannot necessarily manage your iPad or its data using techniques that you use elsewhere.
iOS/iPadOS uses a sandboxed security architecture, where each installed App maintains its own private file-space and data - this often only being accessible from within the App that owns it.
Mail can be accessed using either a specific third-party App, or using the iPad's native Mail App. Different Mail Providers might use different mail-protocols - such as IMAP, POP3 or something else. That said, it is common for Mail Providers to keep all your mail saved on their Mail Server until deleted by you - and a local copy of your mailbox messages being downloaded to your local device. As such, the need to back-up your mail messages is already taken care of by the Mail Provider.
POP3 Mailboxes, where this is your only option, can be problematic. This very old mail protocol allows two principal modes of operation - these being Download and delete (keeping mail only on the client device), or Download and leave a copy on the server (which leaves mail accessible from the server until deleted by a client device). Assuming that you are not using POP3 to access mail, you can dismiss this protocol from further consideration. You should note that the majority of Mail Providers offering POP3 also offer more flexible alternatives that eliminate the inflexibility of POP3 mail.
Returning to device backups...
Given that the sandboxed security architecture prevents Apps from accessing other Apps private data, your options to backup iPad data are native:
How to back up your iPhone, iPad, and iPod touch - Apple Support
While App data can be included within backups, this data cannot be selectively restored. Restoring an iCloud or iTunes backup will replace all device data with that of the backup.
Where data base for Outlook store in iPad Pro
