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This feature is available in Postfix 2.1 and later.The time after which a failed probe expires from the address verification cache.Default values are shown after the parameter name in parentheses, and can be looked up with the "postconf -d" command.Note: this is not an invitation to make changes to Postfix configuration parameters.
Specify a location in a file system that will not fill up.Prior to Postfix 2.6, the response is hard-coded as "450".Do not change this unless you have a complete understanding of RFC 5321.As a migration aid, an attempt to open the file under a non-Postfix directory is redirected to the Postfix-owned data_directory, and a warning is logged.
Examples: Enable caching of failed address verification probe results.
This feature is available in Postfix 2.6 and later.