Blank Mail preferences box after High Sierra 10.13.1

Hi there,

I have looked at the forums here on a solution to fix the mail preferences "blank box". There is no way to adjust these preferences with it blank. I use outlook to do mail merges. Now I cannot because i cannot switch the default mail to outlook. I only use outlook when I mail merge.

Is there a simpler way to fix this without deleting plist folders and re-routing files?

I have a lot of emails that I need to keep and I don't want to risk losing them by deleting. That is not my strong point either.

Thank you,

Scott