You should plan on paying for your witnesses to appear to testify. You can call the court for the daily appearance fee and mileage fee. It should be somewhere in the $30 to $40 a day range and around 20 cents a mile.The "Introducing Digital Evidence in California State Courts" document linked to in this thread does indicate that sending someone to testify as to a text message's authenticity is something cell phone providers do. Were I to subpoena the cell phone provider to send someone to do that would I have to pay for the time that someone spent traveling to and from court, waiting in court for the case to come before the judge, and testifying?
I may have to settle for a signature that certifies authenticity from someone at the cell phone company.
The information about metadata in that document indicates it would help to include the email headers in the email's hard copy. Such headers would make the evidence stronger but would not be irrefutable proof though.
Many thanks for that link. That document linked to contains a lot of information I need to know. I will study it more when I have time.
I am glad you find the information in the link helpful. It sure took some effort to get the link to work.