各位老师：
我的邮件服务器是exchange2003的，收发邮件一直正常，最近一周左右始终收不到一个合作公司发来的邮件，但是一周前是能收到该公司发来的邮件的。收不到的同时，我们是能够给他们发邮件的。对方收到的退信内容如下：
Hi. This is the qmail-send program at x443.secure.ne.jp.I'm afraid I wasn't able to deliver your message to the following addresses.This is a permanent error; I've given up. Sorry it didn't work out.:Sorry, I wasn't able to establish an SMTP connection. (#4.4.1)I'm not going to try again; this message has been in the queue too long.--- Below this line is a copy of the message.Return-Path: Received: (qmail 59647 invoked from network); 7 Nov 2017 15:18:59 +0900Received: from unknown (HELO ?192.168.11.20?) (ng@onlib.com@211.19.63.105)by 0 with SMTP; 7 Nov 2017 15:18:59 +0900Subject: =?UTF-8?B?UmU6IOWFs+S6jumCruS7tuaUtuWPkeeahOmXrumimA==?=To: =?UTF-8?B?55ub5oOg?= , sk@2.comReferences: From: xting Message-ID: Date: Tue, 7 Nov 2017 15:19:01 +0900User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101Thunderbird/52.4.0MIME-Version: 1.0In-Reply-To: Content-Type: multipart/alternative;boundary="------------E16362768A5A79173485A867"Content-Language: en-USThis is a multi-part message in MIME format.--------------E16362768A5A79173485A867Content-Type: text/plain; charset=gbk; format=flowedContent-Transfer-Encoding: 8bit???????????簑??ISP??????????SMTP???????????簑???????????????????????翕????魎鯀?????On 2017/11/07 15:09, ???? wrote:>> ?德???>> ?????????????????????????????昤??????????篋?????????????????> sk@2.com??????>> ??擎曺鮃?????>--------------E16362768A5A79173485A867Content-Type: text/html; charset=gbkContent-Transfer-Encoding: 8bit
请各位老师帮忙分析一下并告知解决办法。
比较急，在线等。万分感谢！