Find external messaging participants in a Yammer network
Verified Admins can use data export to find the names of external participants, and see which conversations and files in their own network are visible to external participants.
Yammer Enterprise networks in the EU Geo do not have external participants.
In the Yammer admin center, go to Content and Security > Export data.
You'll only see this option if you are a verified admin in the Yammer network.
For more information, see Export Yammer Enterprise data.
To identify threads in your network that users from other networks participate in, locate the export folder on your computer, and open the MessageThreads.Outbound.csv export file.
Column D (external_participants) lists the users in other networks that participate in threads in your network, along with their name, email address, and the network ID of the Yammer network that they belong to. The data export reflects the current view of the network. If a user was added but removed before the report was created, that user won't appear in the report.
If you want to remove an external participant, you can use the information from the list to go to the conversation that they're included in and remove them from the conversation. See Remove an external participant from a conversation.