Thank you for your continued feedback. The feature team has this item under review and is considering all options. We will share an update as soon as one is available.
An error occurred while saving the commentPMD commented
I understand that the reasoning behind this is the fact the chat function relies on the OneDrive for business to store the files, and that the guest does not have a OneDrive on the domain. If this is the case, then there needs to be a solution in terms of how these files are stored - such as using the storage space of the user inside the organisation to whom they are chatting. At the moment - this is making the use of this facility impossible and we will need to move over to Slack.