Since iOS 11, scheduled fetch and notifications are happening only for mails received in main Inbox and not for mails received in favorited folders on non push mail account when the sender/ recipient is not configured as VIP in native mail app.
This leaves most received mails out of the purview of scheduled fetch and notifications leaving the mail app useless.
However,in native mail app on iOS 10.3.3 and earlier,the scheduled fetch and notifications used to happen for mails received in favorited folders for even those mail accounts which do not support Push and used only fetch mode even when the sender was not configured a VIP.
Issue remains unresolved in iOS 11.3 beta 2.
This leaves most received mails out of the purview of scheduled fetch and notifications leaving the mail app useless.
However,in native mail app on iOS 10.3.3 and earlier,the scheduled fetch and notifications used to happen for mails received in favorited folders for even those mail accounts which do not support Push and used only fetch mode even when the sender was not configured a VIP.
Issue remains unresolved in iOS 11.3 beta 2.