Fix InvalidOperationException in LookupParentFolders.
Fix InvalidOperationException in LookupParentFolders.

sstraus/MailKit,rajeshwarn/MailKit,dsbenghe/MailKit,nachocove/MailKit,mganss/MailKit,eino-makitalo/MailKit,jstedfast/MailKit,FubarDevelopment/MailKit,matt2003/MailKit,jamie-dainton/MailKit