qmgr_fudge_factor (100)
Obsolete feature: the percentage of delivery resources that a busy mail system will use up for delivery of a large mailing list message.
initial_destination_concurrency (5)
The initial per-destination concurrency level for parallel delivery to the same destination.
default_destination_concurrency_limit (20)
The default maximal number of parallel deliveries to the same destination.
transport_destination_concurrency_limit ($default_destination_concurrency_limit)
Idem, for delivery via the named message transport.
Available in Postfix version 2.5 and later:
transport_initial_destination_concurrency ($initial_destination_concurrency)
Initial concurrency for delivery via the named message transport.
default_destination_concurrency_failed_cohort_limit (1)
How many pseudo-cohorts must suffer connection or handshake failure before a specific destination is considered unavailable (and further delivery is suspended).
transport_destination_concurrency_failed_cohort_limit ($default_destination_concurrency_failed_cohort_limit)
Idem, for delivery via the named message transport.
default_destination_concurrency_negative_feedback (1)
The per-destination amount of delivery concurrency negative feedback, after a delivery completes with a connection or handshake failure.
transport_destination_concurrency_negative_feedback ($default_destination_concurrency_negative_feedback)
Idem, for delivery via the named message transport.
default_destination_concurrency_positive_feedback (1)
The per-destination amount of delivery concurrency positive feedback, after a delivery completes without connection or handshake failure.
transport_destination_concurrency_positive_feedback ($default_destination_concurrency_positive_feedback)
Idem, for delivery via the named message transport.
destination_concurrency_feedback_debug (no)
Make the queue manager's feedback algorithm verbose for performance analysis purposes.