No (Auto When Recieved) option when choosing the Sync Schedule on stock E-mail app. Galaxy S6 Why?

[AC Question]

No (Auto When Recieved) option when choosing the Sync Schedule on stock E-mail app. Galaxy S6

Hi All,

When I go to setup my stock E-mail app on my Samsung Galaxy S6 there isn't an option for me to choose (Auto, when received).

My wife has the exact same phone bought at the exact same time but she does have this option. My mother has the S6 Edge purchased a month later and she has the option to choose (Auto, when received).

Can anyone please give me any help or information on why this is please?

Thank You