Available Since: V1.1.1
Tests if the email address is subscribed to the given list and outputs the appropriate information.
| Parameter | Description |
|---|---|
| listId | The ID of a Campaign Monitor mailing list to test the email address against. |
| The email address of the user to test. | |
| then | The optional string to output if the user is subscribed. |
| else | The optional string to output if the user is not subscribed. |