Lost my dividers in Lotus Notes 8.5 mail view

I have somehow lost my dividers in Lotus Notes 8.5 mail view.

It used to be that High Priority mail was under that heading, Calendar invites under that heading, and then regular mail below that. I don't know what happened but those headers are now gone so all of my mail is just in one giant column.

How do I get it sorted again?

UPDATE: someone told me that all I had to do was click on the WHO a time or two, which acts as a sorter. Done!

its not exactly in the "Who" button. You have to click in the little mail envelope icon that is at the left of the Who icon. With this you can get your mails sorted again by High Importance at the top, then Calendar Events and finally regular mail.

Regards!