Mac Mail mailbox problem with system not marking emails as read and problem with deleting emails
09/18'2019: Have MacOS Sierra version 10.12.6: Having problem with Mac Mail on Mac Airbook. After reading a new email it remains marked as unread. After deleting a read or unread email it remains in the inbox. If I use the pull down menu option a read email can be marked as read. Pull down menu can also be used to send email to Trash folder. Problem is that these things used to happen without using pull down menus. Problem started out of the blue a few days ago.
MacBook Air