When a phone number is put on the SMS kill file, the contact associated to this number is no longer eligible to receive SMS messages.
You can however remove a contact from the list to be able to send SMS again.
How To
From the contact profile
- Once the contact card is displayed, go to the Profile page.
- Click Remove from SMS kill file.
If you don't see this button, it means you don't have the permission to perform this task.
The SMS consent status of the contact, before being put on the kill file, will be restored, and the contact will be eligible to receive SMS again, if it's status allowed it 
.
From Account management > Kill file
- Go to the Search page.
- Search for the number to remove from the list and click the delete icon
. - When asked to confirm, click OK.
If a contact is associated to this number, the contact will recover the SMS eligibility status he had before.