Project emails
Copy the project BCC address onto any email and the thread is stored on the job.
Every project has a tracking address. Find it on the Emails tab.
Put that address in BCC when you write to the client or the design team. The message is filed on the project.
To send from your own domain, verify the domain in Settings → Workspace first.
Quantifiable is not your email host. It only files copies you BCC and mail you send through the app.
Examples
File a tender query reply
Reply to the architect as usual. BCC the project address. The Emails tab shows the thread next to the job, not in a personal inbox only you can see.