collectd/collectd — comment on commit 5c1af1bad76fbd6f8996f09de16cd32f81224354
File:  line 0
By faxm0dem:

The rationale of the original behaviour was the following: if someone only wants critical notifications, he will also want to see when the problem goes away. In your modification, setting notif_severity to FAILURE will discard OKAYs and the admin will never know the failure was repaired.