Emails sorted incorrectly after backup restore

[Jonas Imping]

After I did a backup restore all my emails in for my email accounts are sorted incorrectly. So when I open my email client (Mails on Mac OS X El Capitain) I see emails from 2013 at the top of my mail box with a small date notification "today". But when I open the email the mail date says ... 2013.

I use Plesk 12.5.3 with Postfix and Courier IMAP.

 

[Jonas Imping]

I have to correct myself. When I open the email it says it is from today, too. So every timestamp is not correct.