Email inboxes are one of the many services schools buy, it's not about any promotion and of course Google doesn't promote them, this is a service they provide for money, not some barter. This is like saying they promote a catering provider, furniture manufacturer or paper factory by buying from them... It's not like people aren't capable of using other email providers after using Gmail - email looks just the same regardless of the company (usually works worse though), and people have their own email too, their school inbox is usually not their first nor last contact with it.
Pupils' personal email inbox is their own stuff and completely out of the question. We're talking about school-managed inboxes with addresses ending with the school's domain.
Pupils' personal email inbox is their own stuff and completely out of the question. We're talking about school-managed inboxes with addresses ending with the school's domain.