A domain name was misconfigured due to a dns(bind9) problem in the intranet.
After correction, I waited for kumo for 1 hour and could not be resolved normally until I restarted kumo and the resolution became normal.
What is the default expiration time of kumo?
error log:
“MX lookup for xxxx.xxxx.xxx failed
451 Uncategorized
after 5.118119ms: NXDOMAIN”
The default value for this is “5 minutes”
But I really after 1 hour try still fails,
KumoMTA uses an embedded Hickory resolver and should have a default of 5 minutes.
Is it possible that the local bind is caching too long?
At first I don’t use bind but used 8.8.8.8 in /etc/resolv.conf .Then i changed it to bind9 . after one hour,still mx lookup failed .
So i don’t think it’s local dns cache.. But i not sure