when importing tokens from a csv list with required fields firstname, lastname, email

2 fields are displayed and blank:
"Email status" and "Language"

If I try to send the email invitations, limesurvey returns

"Warning
There were no eligible emails to send. This will be because none satisfied the criteria of:

having a valid email address
not having been sent an invitation already
having already completed the survey
having a token"

My solution: edit csv before importing, put "ok" in field "Email status" and "en" (or fr when needed) in field "Language", import in limesurvey and it works