Messengers as evidence of wages and other circumstances in labor disputes

When resolving labor disputes, messengers become popular as evidence of various circumstances, in particular the amount of wages. In order for the courts to establish the circumstances to which the party refers via the messenger, they must be correct. So, in some cases, the courts take into account the correspondence of the parties in messengers as relevant and admissible evidence, in other cases they refuse to satisfy the claims of the plaintiffs, since the information transmitted through messengers does not meet the requirements of reliability and sufficiency.