How to notarize SMS as litigation evidence?

Unless required by the court, it is not necessary to notarize the SMS when it is used as evidence. But it needs to be copied. You can forward the text message, put your mobile phone on the copier, and you can copy it. Sometimes the court will ask the text message to print an extra dot. When submitting the evidence, just give the mobile phone to the court together with the copy and print.

However, SMS belongs to audio-visual materials, because it is very easy to forge, so it has low probative power and generally needs other evidence to assist.