It isn't possible to cryptographicaly validate messages sent by Hunter Biden using a copy of his mailbox because google (and presumably other mail systems) only

It isn't possible to cryptographicaly validate messages sent by Hunter Biden using a copy of his mailbox because google (and presumably other mail systems) only records the DKIM data on received messages. Mail server place those headers on sent messages, but only the recipient would have the data. So, if we want to validate any DKIM on messages from hbiden@rosemontseneca.com to v.pozharskyi.ukraine@gmail.com we'd need a copy of v.pozharskyi.ukraine@gmail.com's mailbox. And we'd also need for rosemontseneca.com to have been using DKIM at the time. In any case, I don't agree that the title is misleading: In colloquial usage "Foo email" is reasonably used both for email foo sent and email received in foo's box. "Let me check my email" -- for example, is not usually referring to checking email you sent.