1. dst_blocklist_expire

Alias name: dst_blocklist_ttl

How much time a blocklisted destination will be kept in the blocklist (w/o any update).

dst_blocklist_expire = time in s (default 60 s)

2. dst_blocklist_gc_interval

How often the garbage collection will run (eliminating old, expired entries).

dst_blocklist_gc_interval = time in s (default 60 s)

3. dst_blocklist_init

If off, the blocklist is not initialized at startup and cannot be enabled at runtime, this saves some memory.

dst_blocklist_init = on | off (default on)

4. dst_blocklist_mem

Maximum shared memory amount used for keeping the blocklisted destinations.

dst_blocklist_mem = size in Kb (default 250 Kb)

5. use_dst_blocklist

Enable the destination blocklist: Each failed send attempt will cause the destination to be added to the blocklist. Before any send, this blocklist will be checked and if a match is found, the send is no longer attempted (an error is returned immediately).

Note: using the blocklist incurs a small performance penalty.

See also doc/dst_blocklist.txt.

use_dst_blocklist = on | off (default off)