Importing contacts from a csv file: it seems to work but don’t find contacts after

I work with Excel and created a file with names and email addresses, then saved as csv file - comma delimited not Mac or Ms Dos - and use the import feature.  It appears to work but then I cannot find the contacts in my directory.  The csv file does have the needed data in it.  I know the column headings have to match the contact info in my email - perhaps this is the answer.  I've tried different ways to save the info but not getting anywhere.  Thanks!