Here are the formating rules for importing a contact file:
- the file has to be a .csv or .txt and each value has to be separated by a semi-colon
- the header for each column must not include any space or special character
- the email column needs to be named EMAIL
Example :
EMAIL;SURNAME;LAST_NAME xxxxxx@xxx.com;Michael;Loe xxxxx@xxx.com;John;Smith
You may check: Getting started with contact management.