I have uploaded a patch to the primary Postfix source code mirror that adds support to the Postfix SMTP client to rewrite non-delivery status codes and text.
ftp://ftp.porcupine.org/mirrors/postfix-release/experimental/feature-patches/20140315-smtp-bounce-defer-filter-patch ftp://ftp.porcupine.org/mirrors/postfix-release/experimental/feature-patches/20140315-smtp-bounce-defer-filter-patch.sig The description is under the signature. Wietse This is a minimal patch to add support for NDR filtering in the Postfix SMTP client. It should work with Postfix 2.11, 2.12, and it may even work with Postfix 2.10. smtp_bounce_defer_filter (default: empty) Optional filter to rewrite the three-number enhanced status code and the explanatory text in a Postfix SMTP/LMTP client bounce/defer mes- sage. With each bounce or defer request, the user-specified filter is queried with one line of text that is structured as follows: enhanced-status-code SPACE explanatory-text The bounce_defer_filter feature may replace this only with text that has the same structure. Enhanced status codes must have a first numer- ical field of 4 (defer) or 5 (bounce), and the free text field must be non-empty. Other results will result in a warning. Example: The following example turns soft TLS errors into hard errors, by over- riding the first number in the enhanced status code. /etc/postfix/main.cf: smtp_bounce_defer_filter = pcre:/etc/postfix/smtp_ndr_filter /etc/postfix/smtp_ndr_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 # Do not change the following into hard bounces. They may # result from a local configuration problem. # 4.\d+.\d+ TLS is required, but our TLS engine is unavailable # 4.\d+.\d+ TLS is required, but unavailable # 4.\d+.\d+ Cannot start TLS: handshake failure Notes: o This feature modifies error messages that are generated by the Postfix SMTP client, and that may or may not be derived from remote SMTP server responses. In contrast, the smtp_reply_fil- ter feature modifies remote SMTP server responses that may result in email non-delivery or delivery. o This feature will NOT override the soft_bounce safety net. o This feature will apply to all bounce/defer messages from the Postfix SMTP/LMTP client. o This feature will change the enhanced status code and text that is logged to the maillog file, and that is reported tot the sender.
