Tuesday, December 31, 2019¶
Some mailman list members don’t receive any mail¶
Still working on #3339.
It seems that the easiest way to reproduce our problem it to have our own mail server, i.e.postfix at LF does not use a relay. Because then we can at least see what happens. And this is what happens when I try to send something to any recipient @hot.ee:
Dec 30 04:39:52 myhostname-1 postfix/smtp: 1E78DAC52: to=<email@example.com>, relay=mx1.hot.ee[220.127.116.11]:25, delay=6.2, delays=0.02/0.05/6.1/0.1, dsn=4.3.2, status=deferred (host mx1.hot.ee[18.104.22.168] said: 450 4.3.2 Service currently unavailable (in reply to RCPT TO command))
The system admin of hot.ee thinks that maybe I am greylisted and suggests that I increase my timeout, iow to be more patient when waiting for their answer.
As explained here:
# Message delivery time stamps # delays=a/b/c/d, where # a = time before queue manager, including message transmission # b = time in queue manager # c = connection setup including DNS, HELO and TLS; # d = message transmission time.
So the “connection setup including DNS, HELO and TLS” took 6.1 seconds. I looked for configuration settings that might instruct postscript to stop waiting:
$ sudo postconf | grep timeout connection_cache_protocol_timeout = 5s lmtp_connect_timeout = 0s postscreen_upstream_proxy_timeout = 5s smtpd_upstream_proxy_timeout = 5s # (showing only entries with less than 10s)
I looked up the meaning of those settings in the docs but could not find anything that looks worth a test.
I verified that our server is not listed at spamhaus: