No one opens a sealed bag years later in a courtroom to present more than a hundred gigabytes of evidence to the court. You would have your attorney open the envelope in his office and then testify to the fact that he opened the envelope.
There is no such thing as 'undeniable' proof of existence. You present evidence, the other side attempts to deny/discredit the evidence, and then a jury (or judge in a bench trial) decides which side is more credible. They might claim the envelope could be steamed open. They might try calling the notary to the stand. The opposition will always seek some manner of denial.
You could also create a bound book (not 3 ring binder material where pages can be removed/replaced, but a bound book made by Amazon or Shutterfly or whomever) filled with the files and have the book notoraized. There is always an element to electronic files that seems 'easier' to fabricate than paper. In that case, you would have the inside cover notarized.
No case law for you - sorry.
Good luck,
Todd
Answered on Sep 12th, 2014 at 2:28 PM