DNS lookup failure MX for yandex.com
robi last edited by girish
DNS lookup failure: Error: queryMx ESERVFAIL yandex.com.
"Tried all MXs"
Not sure why this would happen or what I can do about it.
Checked FW block list rules, but that's for incoming not DNS lookups.
Does this happen also after you wait some few hours? Often those hit rate-limits quickly and it is always queried when the dashboard fetches the status in the mail view
@nebulon the deferred queue has reached 16,384 seconds.
Where is this coming from? The mail server logs? Can you check if unbound is running with
systemctl status unbound. You can also restart unbound from the Services view.
@girish the Email event log.
unbound is running, although it's log is empty.
why do all logs download to log.txt? they should be unique.
other emails are being delivered just fine.
host -t MX yandex.com 127.0.0.1work on the server?
@girish yes, took a few seconds the first time but it returned the one I found with an online tool.
Is the lookup timeout too short?
@robi I think the delay is the source of the problem. Do you know why it takes so long?
IIUC, nodejs uses c-ares library underneath for DNS queries. And ARES_OPT_TIMEOUTMS has a default of 5 seconds. If it doesn't get a response, it will think it's a failures (since dns resolution is UDP based, it has to rely on timeouts). It doesn't seem like Haraka can configure these timeouts from a quick read of https://github.com/haraka/Haraka/blob/master/outbound/mx_lookup.js
@girish no, but I noticed it took a while when you asked me to run it in CLI too. Not something we control ;-/
Can the DNS query be externalized via shell call to hosts command? Or maybe query twice to get the cached response?