For G Suite.
How can I restrict users to use Gmail App for Smart devices?
It is possible to apply the usage prohibition.
Since the access from smartphones / tablets needs to go through the mobile-carrier-line network (i.e.; external network-outside the company), it is necessary for those users who should be banned from using 「Gmail」 application to belong to the [access policy group denied access through the network outside the office].(*)
(*) The 「Gmail」 application cannot be controlled by entry permission authentication. Please set up the condition as [to deny access through the network outside the office] only.
Besides, whether the behavior of the 「Gmail」 application needs to go through the access control or not, depends on the OS or the account registration procedure.
Concerning the behavior of the 「Gmail」 application, please refer to the article below.
Additionally, it is also necessary to prohibit the settings to directly access to the G Suite without going through the Access Control.
It is possible to set up the usage restriction by the settings in the Admin console of G Suite.
Regarding the setting procedure, please refer to the article below.
Please note that the access restriction through the access control is enabled only when adding the account for the first time.
Hence, if the login onto the 「Gmail」 application has already been achieved, the restriction will be no longer applicable.
In such case, it is possible to forcibly log out from 「Gmail」 application in the way as shown below.
How to forcibly log out the G Suite account from Gmail application
Either one of the following 2 procedures enables the user to forcibly log out the G Suite account from the 「Gmail」 application which the user has already installed onto his/her terminal.
Please log in to the G Suite Admin Console using the super administrator account and perform either one of the following procedures.
･ Change the relevant user’s login password which has been used to log in to the G Suite up until then.
･ Click the link [reset login Cookie] on the password section in the relevant user’s profile menus.
After the steps above, please restart the 「Gmail」 application to confirm that it is forcibly logged out.