The Postfix delivery status filter support is complete as of postfix-2.12-20140321. This can replace the delivery status codes and explanatory text of successful or unsuccessful deliveries by Postfix mail delivery agents.
It was originally implemented for sites that want to turn certain SMTP client soft delivery errors into hard delivery errors, but it can also be used to censor out local information from delivery confirmation reports. Below is text from the RELEASE_NOTES with examples. Wietse This feature is implemented as a filter that replaces the three-number enhanced status code and descriptive text in Postfix delivery agent success, bounce, or defer messages. Note: this will not override "soft_bounce=yes", and this will not change a successful delivery status into an unsuccessful status or vice versa. The first example turns specific soft TLS errors into hard errors, by overriding the first number in the enhanced status code. /etc/postfix/main.cf: smtp_delivery_status_filter = pcre:/etc/postfix/smtp_dsn_filter /etc/postfix/smtp_dsn_filter: /^4(\.\d+\.\d+ TLS is required, but host \S+ refused to start TLS: .+)/ 5$1 /^4(\.\d+\.\d+ TLS is required, but was not offered by host .+)/ 5$1 The second example removes the destination command name and file name from local(8) successful delivery reports, so that they will not be reported when a sender requests confirmation of delivery. /etc/postfix/main.cf: local_delivery_status_filter = pcre:/etc/postfix/local_dsn_filter /etc/postfix/local_dsn_filter: /^(2\S+ delivered to file).+/ $1 /^(2\S+ delivered to command).+/ $1 This feature is supported in the lmtp(8), local(8), pipe(8), smtp(8) and virtual(8) delivery agents. That is, all delivery agents that actually deliver mail. The new main.cf parameters and default values are: default_delivery_status_filter = lmtp_delivery_status_filter = $default_delivery_status_filter local_delivery_status_filter = $default_delivery_status_filter pipe_delivery_status_filter = $default_delivery_status_filter smtp_delivery_status_filter = $default_delivery_status_filter virtual_delivery_status_filter = $default_delivery_status_filter See the postconf(5) manpage for more details.