Use errors to MTA option

Notification message MTA options:  (0 or 1)
DELETED. With the advent of standardized notification handling, this option was deprecated and is now deleted.

The  MTA option controls whether or not the MTA makes use of the information contained in Errors-to: header lines when returning messages. Setting this option to 1 directs the MTA to make use of this header line. A value of 0, the default, disables use of this header line. Note that this default represents a change from the default in early versions of PMDF.