Simple as that.. a unique address I used with Lord of the Rings Online, an online game, was sent official hotels.com spam in Chinese.
Received: from mta.email.hotels.com (mta.email.hotels.com [66.231.82.111]) by my.mail.host with ESMTPS (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256) ; Sat, 23 Sep 2017 00:26:08 +0100 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=200608; d=mail.hotels.com; h=From:To:Subject:Date:List-Unsubscribe:MIME-Version:List-ID:Reply-To:Message-ID:Content-Type; i=info@mail.hotels.com; bh=DKTe3QJJazkAFXWyK6zHLxUqYdg=; b=UGXslgLXZ6IoUGRs5Eh5UtQAuQrBL+8ydzsdoOkP7jE100jtL/bjyCFHe4NMSFaE5PBq5AehwbCq OlVJ/8rljVaMUOP+yVNb0v8EBw04e6LjQQiqR+T5Z2atUf7rOz1MhabG0gH0o8G/IHCH1g/MEAnJ 4xeOZGu6jcSXLzLs4C0= DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=200608; d=mail.hotels.com; b=BJPNLB1/Wbc7dvpS/B3JPoSdcDCgnx3dlMgyqjbOJOG0ev6Aj8Lwrsi+GUnLiWzpzPvyjE8M/9Ia 0rkNniYHQxJSVnErrzFPuEp127iaZciZQY6Tyhw2yZtXjv5ojJLqGgqfCESdii0a7US8MgeLu3Bz y4vfjFJy7W7hRHb8iQ8=; Received: by mta.email.hotels.com id home1o163hs1 for ; Fri, 22 Sep 2017 17:25:59 -0600 (envelope-from ) From: =?UTF-8?B?SG90ZWxzLmNvbSDkuK3lm70=?= To: Subject: =?UTF-8?B?54++5Zyo6KiC77yM6aas5LiK55yB77yB?= Date: Fri, 22 Sep 2017 17:25:58 -0600 List-Unsubscribe: MIME-Version: 1.0 List-ID: X-CSA-Complaints: whitelistcomplaints@eco.de x-job: 177351_21435338 Reply-To: =?UTF-8?B?SG90ZWxzLmNvbSDkuK3lm70=?= Message-ID: Content-Type: multipart/alternative; boundary="kgwiAGSMgprd=_?:" Return-Path: bounce-1935712_HTML-1649075358-21435338-177351-13256@bounce.mail.hotels.com
Poor show and amazing that a large company doesn’t care where they source their mailing lists or even check or require double-opt in confirmation.
X-CSA-Complaints, seen a lot of that in spam recently…