We recently picked up a property to manage that has 10 owners! Some have only a few percentage points of ownership, but they all are interested owners.
The way we handle it is to set the clients up with their respective ownership percentages. Our software then issues any funds going to the owners in the proper amounts. The money is all sent electronically so we do not have to handle paper checks. When funds are sent we email a statement automatically to each owner.
Then, we post their Owner Statement online on a monthly basis showing income, expenses, and supporting invoices. Each owner can then log in and see their report for themselves. Saves postage and handling for sure.