Knowledge base
precached-domains-file<dns>DirectiveA text file with one domain per line; the listed domains are resolved regardless of whether there are messages for them in the queue.precached-refresh-interval<dns>DirectiveSets a refresh schedule instead of the receiver’s record time to live: these domains’ own TTL is ignored.precached-max-domains<dns>DirectiveA ceiling on the number of domains taken from the file; it cannot exceed the number of lines in the file, and extra lines are cut off silently.