There are temporary email services that have a publicly visible inbox, if you have the link, but I suspect that's not what you want. To throw out an idea, could

There are temporary email services that have a publicly visible inbox, if you have the link, but I suspect that's not what you want. To throw out an idea, could you set up some sort of proxy address that forwards to both you and an independent third party? It's not public but it adds an element of transparency.