For the last few weeks, one of my machines (running Debian stable, with
Postfix 2.11.3) gets constantly stuck with things like:
% mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
CDC7364F79 972 Wed Nov 16 08:12:48 monn...@iro.umontreal.ca
(Host or domain name not found. Name service error for
name=smtp.teksavvy.com type=AAAA: Host not found, try again)
emacs-de...@gnu.org
r...@gnu.org
monn...@iro.umontreal.ca
[...]
-- 17 Kbytes in 4 Requests.
Yet `host smtp.teksavvy.com` (which is my relayhost which I set with
`relayhost = [smtp.teksavvy.com]` in my main.cf) responds very happily:
% host smtp.teksavvy.com
smtp.teksavvy.com has address 206.248.188.90
smtp.teksavvy.com has IPv6 address 2607:f2c0:1:2304::5
%
I expected `postqueue -f` to solve the problem, but it didn't.
Instead it just gives me messages in the log along the lines of:
Nov 16 09:32:07 pastel postfix/smtp[22671]: CDC7364F79:
to=<emacs-de...@gnu.org>, relay=none, delay=4759, delays=4759/0.01/0/0,
dsn=4.4.3, status=deferred (Host or domain name not found. Name service error
for name=smtp.teksavvy.com type=AAAA: Host not found, try again)
Now, I can easily fix the problem with:
# /etc/init.d/postfix restart; postqueue -f
but why is it necessary to restart postfix before it notices that
whatever DNS problem might have occurred is long gone?
This problem re-appears pretty much every time I use the machine (it's
suspended in the mean time).
Any idea what my be the culprit and how to fix the problem (other thn
with a cron job that restarts postfix all the time)?
Stefan
