Allie — Email to Billing, Auto

Allie chibi
Hi, I'm Allie a solo attorney.
The system can only see the payment emails — never her whole inbox, because the rest contains confidential client communication.
She needs a secure solution — random SaaS tools can't be trusted with her client data.
The system can't silently corrupt her books, if Wells Fargo changes their format, it has to fail loudly.
Whatever fixes this can't become another thing she babysits
The system has to know what's already been entered — so she never has to go back and check her billing system.
The system has to be delegatable — so she can hand it off if she chooses.