Is microsoftemails.com Safe?

Our exchange server blocked a fake email about the storage limit changes in OneDrive (which we have been getting official emails for coincidentally), and flagged it as ARMALWARE, VIRUS. Part of the header: From: "Microsoft OneDrive" <onedrive@microsoftemails.com> To: [REDACTED] Subject: =?UTF-8?B?SW1tZWRpYXRlIGFjdGlvbiByZXF1aXJlZCDigJMgSW1wb3J0YW50?= =?UTF-8?B?IGNoYW5nZXMgdG8gc3RvcmFnZSBsaW1pdHM=?= ... Reply-To: "No Reply OneDrive" <reply-ff2c10787264-25_HTML-186299394-7231722-1465@microsoftemails.com> x-job: 7231722_4870 ... X-Note: This Email was scanned by AppRiver SecureTide X-Note: SecureTide Build: ***** 6:59:12 PM UTC X-Virus-Scan: V- X-Note: SPF: IP:***** DOM:bounce.microsoftemails.com ADDR:bounce-25html-186299394-4870-7231722-1465@bounce.microsoftemails.com X-Note: SPF: Pass ARMALWARE Failed URIBINARY Code: bWljcm9zb2Z0ZW1haWxzLmNvbQ== X-Note: StopOnFail for ARMALWARE X-Note: Spam Tests Failed: ARMALWARE, WEIGHT10, WEIGHT15, WEIGHT20 X-Country-Path: ->United States-> X-Note-Sending-IP: 136.147.186.3 X-Note-Reverse-DNS: mta3.microsoftemails.com X-Note-Return-Path: ***** ... X-Note: Mail Class: VIRUS

This domain belongs to exacttarget.com, *not* microsoft.com. Although Microsoft certifies it for use by "Microsoft Dynamics" customers, I find no indication that Microsoft itself uses ExactTarget. Subdomains are linked in email appearing to be from Microsoft. Regardless of where they land, clicking those links sends you through third-party ExactTarget which will track you and could potentially affect your interaction at the destination. Considering Microsoft's vast email capabilities, the notion that it needs to use a third-party bulk mailer is implausible, no matter how "official" these emails appear. Reference: ***** Resources: ***** - USA, unknown - Netherlands, TeliaSonera International Carrier - USA, Microsoft Corporation - Norway, PowerTech Information Systems AS - USA, CloudFlare Inc - Europe, TeliaSonera International Carrier - Norway, PowerTech Information Systems AS - USA, Microsoft Corporation - USA, CloudFlare Inc - USA, Microsoft Corporation