Email disabled for elementary student OUs but student sent a message using Google Group

[CHAadmin_KJS]

I have, at the request of administration, disabled Gmail for all our elementary students. This was done at their root OU (ES-Students). However, each grade level also has a Google Group (e.g. 06grade@***.org ) containing those students and teachers. It appears a student somehow messaged the Google Group they were a member of with an inappropriate message. Email log search shows member students had the message bounce, but member teachers received the message. I tried to the Investigation Tool to surface Google Group activity, but I've coming up with nothing. How do I investigate this issue?

[mahz10]

Entiendo lo que comentas, pero no entiendo que necesitas concretamente. ¿Quieres saber quién envió el mensaje?

[SteveHarmon]

Check that the service Groups for Business is not turned on for the Student OU (in fact, we turn off that service for most everyone, staff included, unless there is a clear reason why they need that access). That service does not affect whether a user can be in a group, it affects if they have access to groups.google.com and can manage a group they are a part of (most people do not need this type of access).

Make sure that you leave this service on for you and your tech group. Then you can go into that service and look for the group that was affected to review the history and settings for it. One option would be to turn on moderation so that someone (the teacher or principal) can moderate which emails get sent through to that group.

Hopefully this helped answer your question!

[don_b_nashville]

This doesn't address your issue directly, but here's some info from Chromebook classroom searching logs that I found helpful in general, and maybe someone else will get some value from it: 

https://www.chrmbook.com/chrome-log-event-search/

[don_b_nashville]

Here's another specifically on Groups events: 

https://support.google.com/a/answer/6270454?hl=en&fl=1&sjid=14055070385293534771-NA

[npl]

Would the user has used the web posting option in groups to post to the group, as far as I am aware this does not require gmail.
You can turn off "Allow web posting" see https://support.google.com/a/users/answer/10376887?hl=en