Request USPS Electronic Return Receipt with Unique ID

This is an optional api that can be use to retrieve USPS Electronic Return Reciepts for Certified Mail, Priority Mail and Priority Express Mail."
+ "This call is for API customers that need to associate a unique id to each mail recipient that will be used to identify a specific mail piece for pulling electronic return reciepts."
+ " In order to use this feature your uploaded address list must contain column with the heading of c2m_uniqueid and each address must have a unique ID associated with it.