response_transcode_pattern — the regex pattern for comparison to a server response
response_transcode_pattern = "
This feature requires the “response_transcode – Module”.
When the SMTP response from a remote sever indicates an error—the response code falls in the range 400 to 599—then that response is compared to the response_transcode_pattern regex. If it matches, the response is replaced with the string in response_transcode_replace; dollar variable expansion is performed, so the entire matching response can be substituted with $0 and the strings matched by grouping parentheses in the regex with $1, $2 and so on. The replacement response is used for deciding what to do with the message next, how it is logged and bounce processed.
Since it is possible to rewrite permanent errors as temporary errors, use this module carefully. Resubmitting mail that a remote server has already rejected with a permanent error can be seen as a hostile action.
This option is used in conjunction with
response_transcode_replace. See below for an example pairing:
response_transcode_pattern = "454 no such user ('.*')" response_transcode_replace = "554 no such user $1"
In this case a 'soft' bounce is converted to a "hard' bounce so that there are no further deliver attempts.
This option is valid in the binding, binding_group, domain, and global scopes.