Add a number/numbers to a 'send' group (excluding 'merge' groups).
Name ID of the group to add the numbers to.
numbers The MSISDN (mobile number) you wish to add, if you want to add more then one use a comma delimited list.
an integer with the total of added numbers to the selected group.
Specific error codes:
A number was not of a valid format.
error code 404 is reported if the group does not exist. See General error codes.