How to configure postfix so that mail are received using time from the server

[Eric Kom]

Good day folk,
I ran Postfix with Dovecot as a mailbox for years now.
I noticed that, when a sender sent mails, the mailbox received it using
the date and time from the sender machine not a server one.
Which make the receiver mailbox saving the mails at the wrong time.
Please can someone help me if something have to be done regarding this
issue?
Thanks