If you go for free all in one solution for your business, and self-host on your server, then you can use any one of the free ERP-CRM Software given below:-
- Apache OFBiz
- Axelor ERP
- xTuple PostBooks
These softwares are complete Enterprise resource planning systems. For free Email marketing automation you can use free and open source web application.
For specific accounting, bookkeeping and employee management you can use free and open-source software