So I’m doing something like this for a legal case I am dealing with for giggles. AI is absolutely giving me bogus answers that I have to fact check. Not sure I would trust it to reconcile items.
Do you have to trust it? Have the AI built a list of all the invoices it can find in your email then a separate application reconciles that against your statements. The AI might miss something or invent something, but the mismatch list you get back should be short.
It wouldn't be perfect, but maybe it would be better than having to do it all manually.