ProWorkflow has its own messaging system that will help you collate all project communications into a single space where internal and external members can see them.
They are sorted into two levels, Item Messages and Project Messages. This means you can quickly identify which communications are about a specific task, activity, material etc, or if they relate to the project as a whole.
Item Messages can be accessed/seen/sent from the detailed Item pop-up. Click on an Item name from your list to open this screen:
Although item messages can be sent/seen from within that detail screen, they will also appear in the general project messages area.
On a technical level, these communications will be sent via a ProWorkflow domain. For each message thread that is created, a unique email address (with the ending @notify.proworkflow.com) will be created and used as the actual sender address for any communications stemming from the thread. Any communications forwarded to this generated address will be added as responses in the thread.
Unfortunately, you are not able to forward email communications directly into a project, which means communications will need to have started in ProWorkflow.