For a hassle free user experience, Canary Mail allows the admin to manage the email provider settings.
1) You can specify your Organization’s email provider settings via Configuration > Email Setup > +.
2) Select the email provider for which you want to specify the settings.
3) Users will see these provider(s) at the top of the list in the in-app ‘Add Account’ screen.
4) Selecting the email providers will allow you to delete them in bulk.