Do you believe screenshots?

The question arose - how to verify the authenticity of screenshots? What method can be suggested for checking if the person and source are unfamiliar to you, and it is impossible to give a direct link to the page, for example, is this your mailbox?
PS. In the Ministry of Internal Affairs and other structures, such screenshots are evidence, as are printed pages, for example, of a forum.




PPS I do not want to say that someone once deceived someone like that, just decided to raise this topic.