Contacts listed on the kill file appear on the same list for all projects within the account. There is a list for emails and another for SMS (if the SMS module is activated). A contact on the kill file does not receive any communication for the linked channel and that applies to all projects of the account. When you remove a contact from the kill file, the sendings for Email or SMS will restart. Note that quarantine can also affect sendings.
Different reasons can cause the addition of a contact to the kill file. For the email kill file, the most frequent case is when the contact reports the message as spam or junk. The addition of the contact is done automatically by the system. For the SMS kill file, a contact may have answered STOP. Also, a contact can be added manually after a verbal or written request from the customer.
Consult the Kill File
Go to Account in the lower part of the left menu:
In Kill file you can consult the kill file for the Email or the SMS channel:
You can click on Complete list or Search to find contacts using specific filters. For example, if you want only Outlook addresses in your results, use %outlook% as a filter. To see the list, you must have admin access to the account.
Adding/Removing Contacts from the List
List
You can remove a contact directly from the list by clicking on the garbage icon:
Manual Adding
In the option Add, type one email address or one phone number* per line: 
*For SMS, the phone number must be between 3 and 16 characters and start with a +.
Import
In the Import option, upload a text file containing emails or phone numbers to add to the list: 
Contact's profile
In the contact's profile, you can add or remove a contact by blocking or unblocking the sendings for Email or SMS channels.
Results
You can see the reasons why the contact has been added to the kill file in the Source row:
To export the list in Excel or CSV, click Export in the lower right.