Rated 3 out of 5 stars

Unfortunately I was not able to get it working properly in TB 60 beta 7 (I installed this add-on for the first time). It was not so easy to sort out how to use it, the below comments helped a lot. My settings in about:config are:

extensions.set-default-columns@clear-code.com.columns
threadCol,flaggedCol,attachmentCol,subjectCol,senderCol,accountCol,dateCol,receivedCol,sizeCol,xspamscoreCol,junkStatusCol

extensions.set-default-columns@clear-code.com.order
threadCol,flaggedCol,attachmentCol,subjectCol,senderCol,accountCol,dateCol,receivedCol,sizeCol,xspamscoreCol,junkStatusCol

But new folders don't have the specified columns in their default view.

This review is for a previous version of the add-on (1.1). 

Rated 5 out of 5 stars

I have written a review for the previous version: everything was fine except that there was no possibility to reorder the columns.

The new version fixed that issue, now it's just perfect!

Check my previous review for a way to change columns for *existing* IMAP folders using this add-on.

This review is for a previous version of the add-on (1.1).  This user has a previous review of this add-on.

Rated 4 out of 5 stars

Does what it says - sets the default column layout for new folders.
There is no configuration UI, it is done by editing a comma-separated list variable in about:config. The name is mentioned in the addon's details, but it's not obvious. The process is a bit tricky since the columns are referred to by their code names, but a lot can be inferred from the names and their ordering. The starredCol column is not listed as default. The addon requires manual install from disk.

This review is for a previous version of the add-on (1.0).