Extmail，不能向域外發送郵件
Extmail郵件系統，域內之間收發以及域外往域內發送郵件都正常，只有域內郵箱往外不能發送。
postqueue -p 可看到發送的郵件一直在隊列中，提示如下：
C8D8194053 1957 Thu Dec 6 18:41:34 new1@test.com.cn
(Host or domain name not found. Name service error for name=163.com type=MX: Host not found, try again)
abc@163.com
A8F8B9406A 1239 Thu Dec 6 21:58:39 new1@test.com.cn
(connect to freemx4.sinamail.sina.com.cn: Connection timed out)
abc@sina.com.cn
日誌中相關信息：
Dec 6 21:58:39 mail postfix/pickup: 66C9894069: uid=1000 from=<new1@test.com.cn>
Dec 6 21:58:39 mail postfix/cleanup: 66C9894069: message-id=<20071206135839.66C9894069@mail.test.com.cn>
Dec 6 21:58:39 mail postfix/qmgr: 66C9894069: from=<new1@test.com.cn>, size=505, nrcpt=1 (queue active)
Dec 6 21:58:39 mail postfix/smtpd: connect from mail
Dec 6 21:58:39 mail postfix/smtpd: A8F8B9406A: client=mail
Dec 6 21:58:39 mail postfix/cleanup: A8F8B9406A: message-id=<20071206135839.66C9894069@mail.test.com.cn>
Dec 6 21:58:39 mail postfix/qmgr: A8F8B9406A: from=<new1@test.com.cn>, size=1239, nrcpt=1 (queue active)
Dec 6 21:58:39 mail postfix/smtpd: disconnect from mail
Dec 6 21:58:39 mail amavis: (02893-03) Passed CLEAN, <new1@test.com.cn> -> <abc@sina.com.cn>, Message-ID: <20
071206135839.66C9894069@mail.test.com.cn>, mail_id: Ro1+zmkz4bRV, Hits: 2.851, 292 ms
Dec 6 21:58:39 mail postfix/smtp: 66C9894069: to=<abc@sina.com.cn>, relay=127.0.0.1:10024, delay=0.44, de
lays=0.13/0.01/0/0.3, dsn=2.6.0, status=sent (250 2.6.0 Ok, id=02893-03, from MTA(:10025): 250 2.0.0 Ok: queued as
A8F8B9406A)
Dec 7 16:03:37 mail postfix/anvil: statistics: max connection rate 1/60s for (smtp:219.234.223.25) at Dec 7 16:00:14
Dec 7 16:03:37 mail postfix/anvil: statistics: max connection count 1 for (smtp:219.234.223.25) at Dec 7 16:00:14
Dec 7 16:03:37 mail postfix/anvil: statistics: max cache size 1 at Dec 7 16:00:14
《解決方案》
看日誌,已經SEND出去了!日誌正常!請查看網路和DNS!
《解決方案》
DNS和網路確認不存在問題
往域外發送的郵件一直在隊列中，smtp連接域外郵件伺服器時始終提示連接超時
