Why are certain folders grayed-out & italicized?

I have two folders - both italicized and grayed out - but don’t know how that happened.  Looked at the properties of grayed-out folders and and NOT grayed-out ones.  They were the same.  Read a post from 3 yrs ago on the same question but no one answered it specifically.  Why are certain folders grayed-out & italicized?  How do I change those folders to regular ones?

Hello Bill,
this could be an error that happened when you tried to move or delete certain folders but your mail server stopped you from doing this. This problem should be fixed if you run a repair on your account.
Click the account name in your mail list > Properties > Repair and run a repair on your account. Wait for a full resycnhronization to finish.

Regards,
Olivia