dns: sendto() failed: Connection refused at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/DnsResolver.pm line 411, line 7613

USER反應今天的信都收不到，看了一下MAIL SERVER LOG，發現有下列訊息

Oct 21 06:14:52 mail spamd[1130]: spamd: connection from mail [127.0.0.1] at port 49154

Oct 21 06:14:52 mail spamd[1130]: spamd: setuid to sharon.wang succeeded

Oct 21 06:14:52 mail spamd[1131]: spamd: connection from mail [127.0.0.1] at port 49155

Oct 21 06:14:52 mail spamd[1131]: spamd: setuid to mailbak succeeded

Oct 21 06:14:52 mail spamd[1131]: spamd: processing message <c4128db6ae7249d481212b1e336d3e53@ACAS32.corp.ardentec.com> for mailbak:512

Oct 21 06:14:52 mail spamd[1130]: spamd: processing message <c4128db6ae7249d481212b1e336d3e53@ACAS32.corp.ardentec.com> for sharon.wang:553

Oct 21 06:14:53 mail spamd[1131]: dns: sendto() failed: Connection refused at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/DnsResolver.pm line 411, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: Use of uninitialized value in string ne at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/AsyncLoop.pm line 174, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: plugin: eval failed: oops, no key at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/AsyncLoop.pm line 174, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: dns: sendto() failed: Connection refused at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/DnsResolver.pm line 411, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: Use of uninitialized value in string ne at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/AsyncLoop.pm line 173, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: dns: sendto() failed: Connection refused at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/DnsResolver.pm line 411, <GEN13160> line 7613.

Oct 21 06:14:53 mail spamd[1131]: Use of uninitialized value in string ne at /usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/AsyncLoop.pm line 173, <GEN13160> line 7613.

信件卡在佇列區無法將信送到使用者信箱。

為了先讓信件可正確寄發，先停用spamassassin 套件。
[root@mail incoming]# /etc/rc.d/init.d/spamassassin stop

停用Postfix呼叫 spamassassin 程序
[root@mail incoming]# vim /etc/procmailrc
將這兩行註解掉
:0fw
| /usr/bin/spamc

查了網路上的訊息，應該是說DNS無法正確解析。

http://mail-archives.apache.org/mod_mbox/spamassassin-users/200903.mbox/%3C200903240309.30217.Mark.Martinec+sa@ijs.si%3E
==========================================================
Chris,

> Mar 23 18:01:08 localhost spamd[3676]: dns: sendto() failed:
> Connection refused
> at /usr/lib/perl5/site_perl/5.10.0/Mail/SpamAssassin/DnsResolver.pm
> line 395, <GEN71> line 45.

man 2 sendto

  [ECONNREFUSED]     The socket received an ICMP destination
         unreachable message from the last message sent.  This typically
         means that the receiver is not listening on the remote port.

Your DNS server is not reachable – either it is not running, or
is being blocked by a firewall, or your <chroot>/etc/resolv.conf
is misconfigured.

  Mark
===========================================================

果然發現DC  的DNS服務是關閉的，啟動後再恢復spamassassin 運作即可正常。至於DC DNS為何會關閉，也看不出任何錯誤訊息，再觀察觀察。