Have a look in 'View' and make sure you have got 'Show all Messages' ticked and not 'Hide Read Messages'
That varies slightly depending on which email client you are using so it is whichever toolbar menu takes you to that setting.
This thread is now locked and can not be replied to.
Best Cyber Monday deals 2015 live blog: Best UK Cyber Monday tech deals, sales, discounts & offers
1995-2015: How technology has changed the world in 20 years
Harry Potter's graphic designers showcase magical props & posters in new exhibition
Apple rumours & predictions 2016: What to expect from Apple in 2016
Synology invites you to visit them at IP EXPO - Europe’s number one IT event on 7th-8th October. Register HERE for free and join them at stand DD8