Mail from internal user moved to junk and can not move back

Akshay_Mane  

Modified the original topic for proper information.

Here's a problem mail header:

Received: from MBX.[Our domain] (192.168.1.206) by MBX.[Our domain] (192.168.1.206) with
Microsoft SMTP Server (TLS) id 15.0.1293.2 via Mailbox Transport; Thu, 25 Apr
2019 10:53:04 +0800
Received: from MBX.[Our domain] (192.168.1.206) by MBX.[Our domain] (192.168.1.206) with
Microsoft SMTP Server (TLS) id 15.0.1293.2; Thu, 25 Apr 2019 10:53:04 +0800
Received: from MBX.[Our domain] ([::1]) by MBX.[Our domain] ([::1]) with mapi id
15.00.1293.006; Thu, 25 Apr 2019 10:53:04 +0800
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: binary
From: <[Internal user A]@[Our domain]>
To: <[someone else]@[Our domain]>
CC: <[Problem mailbox]@[Our domain]>
Subject: =?gb2312?B?suLK1A==?=
Thread-Topic: =?gb2312?B?suLK1A==?=
Thread-Index: AdT7EilzQrnSPbf3Q5y3XFXB5g17Iw==
Date: Thu, 25 Apr 2019 10:53:03 +0800
Message-ID: <522197462de04a7f8d700faad6120266@MBX.[Our domain]>
Accept-Language: zh-CN, en-US
Content-Language: zh-CN
X-MS-Has-Attach: yes
X-MS-Exchange-Organization-SCL: -1
X-MS-TNEF-Correlator: <522197462de04a7f8d700faad6120266@MBX.[Our domain]>
MIME-Version: 1.0
X-MS-Exchange-Transport-FromEntityHeader: Hosted
X-MS-Exchange-Organization-MessageDirectionality: Originating
X-MS-Exchange-Organization-AuthSource: MBX.[Our domain]
X-MS-Exchange-Organization-AuthAs: Internal
X-MS-Exchange-Organization-AuthMechanism: 04
X-Originating-IP: [192.168.1.245]
X-MS-Exchange-Organization-Network-Message-Id: f216c941-2249-4ace-f9d0-08d6c929234d
Return-Path: [Internal user A]@[Our domain]
X-MS-Exchange-Organization-AVStamp-Enterprise: 1.0