Deleting contacts is a permanent action that cannot be undone.
Note that interactions from deleted contacts will still remain in the All communications box but without the contact's name. You can re-link a set of interactions (SMS and calls) with a deleted contact by re-creating the contact record with the same number.
To delete Contacts;
Step 1: Click on the People tab and check the box next to the Contact that you want to delete or check multiple boxes if you are deleting more than one contact. Note: You can check the entire contact list for deletion by clicking the checkbox below the trash icon.
Step 2: Click on the Trash can icon to start the delete process. This will open a pop up window where you can confirm the delete action. In case you selected more than one contact, for example five you will shown that 5 contacts have been selected.
Step 3: You will get a notification such as the one below confirming the deletion.
Note: You can also delete Contacts from the within the Contact editor. There's a button to do this at the bottom of the contact editor form.
Deleting Contacts in Groups and Smart groups.
Open the Group or Smart Group with the contacts that you want to delete and follow the steps above. Contacts deleted from within these are also removed permanently from the contact list.