Is this for all your inbound mail? Or just for one, some, senders?
Is your system date/time/time zone correct on your computer?
Please mention your version/mode/SP level of Outlook (from Help | About),
what kind of mail account(s) you use, and any other pertinent details.
The date/time being displayed depends on the date, time, timezone and DST
settings of the computers that are involved; sender, receiver and
mailservers.