I found a solution to get the email activities for users, but the examples in the API reference were not so straight-forward, and they were spread out on several pages. I ended up using User Usage Report from the GSuite Reports API (as suggested in a comment on the original question): https://developers.google.com/admin-sdk/reports/v1/guides/manage-usage-users
Sample call:
GET https://www.googleapis.com/admin/reports/v1/usage/users/all/dates/2018-05-21?parameters=classroom:last_interaction_time,accounts:last_login_time,accounts:last_sso_time,gmail:last_access_time,gmail:last_imap_time,gmail:last_interaction_time,gmail:last_pop_time,gmail:last_webmail_time
This way I was able to get not only email activities, but also Classroom last interaction time and GSuite last login time and Last SSO time.
Sample user response:
"entity": {
"type": "USER",
"customerId": "customerId",
"userEmail": "sample@email.com",
"profileId": "profileId"
},
"parameters": [
{
"name": "classroom:last_interaction_time",
"datetimeValue": "1970-01-01T00:00:00.000Z"
},
{
"name": "accounts:last_login_time",
"datetimeValue": "2018-05-18T14:46:11.000Z"
},
{
"name": "accounts:last_sso_time",
"datetimeValue": "1970-01-01T00:00:00.000Z"
},
{
"name": "gmail:last_access_time",
"datetimeValue": "2018-05-18T08:43:15.000Z"
},
{
"name": "gmail:last_imap_time",
"datetimeValue": "1970-01-01T00:00:00.000Z"
},
{
"name": "gmail:last_interaction_time",
"datetimeValue": "2018-04-23T07:08:40.000Z"
},
{
"name": "gmail:last_pop_time",
"datetimeValue": "1970-01-01T00:00:00.000Z"
},
{
"name": "gmail:last_webmail_time",
"datetimeValue": "2018-04-23T07:08:44.000Z"
}
]