We are building a collaboration tool for a law agency. And we want users to send and receive mails inside our web-application. Users should only send mails with attachments/documents to other recipients using the app and view mails in webapp. App should work as a virtual room, and Users cannot sync to outlook or forward to Gmail.
Yes, we could technically use Gmail or SendGrid, but we are looking for a cost-free solution.
Any thoughts on how we can achieve this? Can we achieve the same as messages and not mails?