Current situation: Currently, there is no option to add additional recipients to an existing transmittal.

For Reviews, this is possible via "Send email notification" button inside the history log (as long as Review isn't closed).


For now, the only workaround is to forward the e-mail to additional recipients inside MS Outlook.
Unfortunately, this process bypasses BIM360 and all affected actions aren't logged properly within the platform.
Idea: Allow adding recipients after transmittal has already been created.