On Fri, Feb 08, 2013 at 09:29:22AM +0100, Angel L. Mateo wrote: > We are having problems with dns lookups to one domain. I know is > not a postfix problem, but a dns configuration error in that domain. > But it is affecting our servers.
The easiest work-around is to stop sending mail to the unreachable domain. > > The problem is that whenever the relay server receives a mail > directed to that domain, I get the error "conversation with <mail > server> timed out while sending MAIL FROM". And as list server group > messages, all recipients in that group as rejected. Your DNS timeouts are too long (perhaps tunable via /etc/resolv.conf on the relay), or SMTP timeouts too short (tunable via main.cf on the list server). You posted no log entries, or "postconf -n" so further help is not possible. > So I would like to configure some kind of dns lookup timeout in my > relay servers, so if the query is not answered I could reject the > message with a dns error instead of timing out the connection. > > Is this possible? How? Use VERP to send list messages to one recipient at a time with a variable sender address that allows you to track down the original recipient when processing bounces. With VERP only the problem domain will have delivery issues and you'll be able to purge persistently undeliverable recipients from your list. -- Viktor.