Please explain what you are wanting to do. "edit mail folder" is too vague for a response. Thank you.

I have some folders I use to use but no longer need for storing old E-mails. I want to delete them but can't find anything about doing that.

I have some folders I use to use but no longer need for storing old E-mails. I want to delete them but can't find anything about doing that.

And yet that is still not enough to make a definitive answer. Fundamentally you can not delete ALL folders, only some. Right click the folder in the folder pane. If you can delete it there will be a delete menu entry. Otherwise you have to keep it.

If it is an account you no longer use. Access account settings and use the account actions button to remove it.

Note that the local folders (special) account can not be removed, nor can most of it's folders. You can delete the content of the folders however.