I am using Outlook 2013.  I have the preview pane set to display two lines of text per message, with the reading pane displayed to the right.  I receive a lot of email and often sort them by sender to process them more effectively.  When I delete a message from a particular sender, the preview pane resets and goes to the first sender, (the one that starts with "a").  For example, say I have sorted my email and have all the email from sender LLL.  When I delete one of the emails from sender LLL, the preview pane resets and displays emails from sender AAA.  The inbox keeps the sort and I can scroll back down to sender LLL but this is a real waste of time.  Please advise. Thanks.  

Sorry, I cannot reproduce your behavior.

When I sorted the message by Send (Choose "By From") and delete the message item from sender Rex, the preview pane would not go back to the email from sender the top one.

Please try to test it in Outlook safe mode to check if there is any macros or add-ins affect that.  (Run "Outlook.exe /safe")

Please also try to start Outlook with the command-line switch "Outlook.exe /cleanviews" to restores default views

To create a new profile is also proposed. http://support.microsoft.com/kb/829918

Tony Chen
TechNet Community Support

Used the /safe option.  Problem seemed gone so I started to delete one hundred or so emails throughout my inbox.  Problem returned.

Using /cleanviews not to see if this helps.

Have you disable the add-ins currently?

Tony Chen
TechNet Community Support