Forking during queue runs

When the ForkEachJob (Y) option is set, sendmail forks before each individual message while running the queue. This prevents sendmail from consuming large amounts of memory, and so it may be useful in memory-poor environments. However, if the ForkEachJob option is not set, sendmail keeps track of hosts that are down during a queue run, which can improve performance dramatically.

If the ForkEachJob option is set, sendmail can not use connection caching.