Why does 4KB appear in acct. size? Rated 4 out of 5 stars

Why does a constant "4KB" appear in the Size column on the line of the name of Local Folders and my Comcast email account, but not for my AOL email account? The Size column should be blank on the line of each of the mail account (and Local Folder) names.

How can I get rid of the "4KB" ?

This review is for a previous version of the add-on (1.1.4).  This user has 4 previous reviews of this add-on.