What is a good platform for distributing business documents?

Background - I'm a programmer at a financial services startup.

My boss came to me today and asked if I know of a platform/service that can manage distributing legal/reporting documents to our clients. With very little idea of what kind of platforms manage client subscriptions in this way, I mentioned just using Google Docs, which he doesnt like because it would require effort on his end to organize the delivery/sharing of documents with our clients, and it would require our clients to have Google accounts which they dont all have. Something that can manage sending reporting emails is more along the lines of what we need. I dont have any idea what to look for to solve this problem - document sharing platforms like Google Docs/Dropbox clearly aren't a right fit. Any suggestions of services that can fit the need for distributing documents or ideas on what to look for?