I use this outlook for my office email account (configured with Microsoft Exchange). 
I have many folders and subfolders under Inbox. I use the drag and drop method of moving his emails into their respective folders. 

Often, while I am checking emails / dragging an email to a folder, the entire pane of folders will collapse, expand, and finally collapse back to the complete unexpanded state. I will then have to expand folders and sub folders all over again everytime, this is very unproductive and frustrating. 
Can any Microsoft expert help please?

Thanks a million. 

Nina 

I recommend that you post this in the Outlook Forum:  http://social.technet.microsoft.com/Forums/en-US/outlook/threads

Hi,

As per the information and details provided by you, to solve this issue, please follow these steps: -

If your default startup folder of Outlook is your Inbox folder, then Outlook will always expand that mailbox to Inbox folder even when your Inbox folder has been added to your Favorites list. To counter this, set your default startup folder to Outlook.

To set your default startup folder:

• Outlook 2013

File > Options > Advanced > option group: Outlook start and exit > Start Outlook in this folder.

I hope this information will be helpful for you.

Thanks and regards

Shweta@G

Hi,

I understand your question, please try to take the below steps:

View-> View setting ->group by ->select available fields from 

Then set the Expand/collapse defaults  option is all expand

If it doesnt work, I suggest you can ask question in Microsoft Outlook forum to confirm whether it can be achieved by other methods:

https://social.technet.microsoft.com/Forums/office/en-US/home?forum=outlook    

Best Regards,

David