Adds an email to a list, when giving the list id. Also supports custom columns if they already exist in the list just pass the column name via the request.
Note: the column names are stored in our system as lowercase a-z0-9 spaces are removed.
| Argument | Data Type | Required | Description |
| id | integer | Yes | id of the list |
| string | Yes | email address to add to the list. |
| XML Response | JSON Response |
| <response> <success>Email Added to List</success> <id>22</id> </response> |
{
"success": "Email Added to List",
"id": "22"
} |