What all the above shows is that there is enough woffle and geekyness in the answer to the questions to confuse everyone but a real nerd. The beak will not be a real nerd. He/ she will likely be a lawyer, will understand the post system but wont understand the email system so there is endless room to obfuscate and confuse him / her. All of which will leave the beak feeling very doubtfull and the case unproven.
Might be worth having a look at
https://www.bsigroup.com/en-GB/bs-10008-electronic-information-management/ Apparently this is one of the documents used by courts to decide if electronic documents are admissable as evidence.
