Updating the destination list of delivery server has failed
Specify 1 to implement a crude form of greylisting, that is, always defer the first delivery request for a new address.Examples: The delay between queries for the completion of an address verification request in progress. Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).The Postfix configuration file specifies a very small subset of all the parameters that control the operation of the Postfix mail system.Parameters not explicitly specified are left at their default values.The time after which a failed address verification probe needs to be refreshed.How many times to query the verify(8) service for the completion of an address verification request in progress.The table is maintained by the verify(8) service, and is opened before the process releases privileges.
This feature is available in Postfix 2.6 and later.
To recover delete (NOT: truncate) the file and do "postfix reload".
Postfix daemon processes do not use root privileges when opening this file (Postfix 2.5 and later).
When this feature is disabled, Postfix will generate an address probe for every lookup.
This feature is available in Postfix 2.1 and later.
Note: this is not an invitation to make changes to Postfix configuration parameters.