Legal Question in Civil Litigation in California

You need to print out the e-mail with the date and sending information on it and then testify that that is an accurate and true copy of the e-mail you received [just as admitting a photo into evidence]. But the judge can weigh the strength of the e-mail and may know now easy it is to make a phoney one so may put little weight to it.

There is no rule against using emails as evidence. But most emails are hearsay, and hearsay is often inadmissible. You will have to show that the emails either aren't hearsay or that they fall into one (or more) of the many exceptions to the hearsay rule. You will also have to show that they are relevant to what you are trying to prove, that they are not overly prejudicial, that they are authentic, etc.

The rules of evidence are very complex, as are other procedural rules you will have to follow. You should get a lawyer if at all possible4. Even if you can't afford to have one represent you, you should try to get guidance and advice so you will be better able to represent yourself.

Good luck.

You have to show that they are relevant, properly authenticated, and show that they meet an exception to the hearsay rule.