Hi Elizabeth,
I have 1000 companies so considerably less to monitor than you. However regardless of the number of companies, it’s all about processes, so I’ll share what I’m doing.
Initially I didn’t like the electronic receipt of invoices either, but now that I’ve got used to it, it’s saving me time! I don’t have to scan the invoices or manually create letters or emails, everything is done through CAS360. There’s also no need to file the invoices into our Document Management system, because I know I can always access copies via CAS360.
I process the incoming invoices a couple of times a week. I have CAS360 open on two screens. On one screen I select Documents, All ASIC invoices. On the second screen I select Company.
I work my way through the new invoices, using the first screen to view the invoice, and the second screen to send the invoice to the client via email using the Debt Alert functions. At this point I can also check that the current debt balance still matches the amount shown on the invoice.
Once I’ve sent an invoice I update the status of the invoice on the first screen to ‘Sent to Client’ so each time I come back to this screen I can quickly see which invoices are new and need to be processed.
With regard to ASIC sending overdue notices direct to company directors, I believe this would be the case regardless of whether you were receiving the initial invoices by post or electronically. It’s my understanding that ASIC sends correspondence directly to officeholders only when there has been no response to the correspondence sent to the main contact address (either the Agent or the registered office if no Agent is appointed).
Hope this helps! 
