MS Azure IPs blacklisted RRS feed

  • Question

  • Dear Support Team,

    e-mails sent via my Office 365 account from the app in MS Azure get rejected by receiver's incoming mail servers. It's caused by the fact, that originating IP address belonging to MS Azure is blacklisted in spamhaus (for example What do I have to do in order to make sure the e-mails will reach recipients?

    Kind regards,


    Tuesday, June 27, 2017 9:00 AM

All replies

  • Are you sure it's Azure IP?

    When you send email with O365 account, email should go over O365 SMTP as Azure doesn't allow use of local SMTP. So, I think problem is with Office 365 IP address, not Azure.

    Mustafa Toroman, Azure MVP

    Tuesday, June 27, 2017 9:10 AM
  • I'm getting the following response:

    Delivery has failed to these recipients or groups:
    Your message wasn't delivered because the recipient's email provider rejected it.

    Diagnostic information for administrators:
    Generating server: AM5PR1001MB1058.EURPRD10.PROD.OUTLOOK.COM
    Remote Server returned '550 5.7.501 Service unavailable, Client host blocked using Spamhaus. To request removal from this list see http://www.spamhaus.org/lookup.lasso (AS16042849)'
    Original message headers:
    Authentication-Results: gmail.com; dkim=none (message not signed)
     header.d=none;gmail.com; dmarc=none action=none header.from=mydomain.com;
    Received: from RD00155D49BC06 ( by
     AM5PR1001MB1058.EURPRD10.PROD.OUTLOOK.COM (2603:10a6:203:12::17) with
     Microsoft SMTP Server (version=TLS1_2,
     cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1220.11; Tue, 27
     Jun 2017 07:52:26 +0000
    MIME-Version: 1.0

    From: no-reply<at>mydomain.com
    To: my-email<at>gmail.com
    Date: 27 Jun 2017 07:52:25 +0000
    Subject: Confirm your account
    Content-Type: text/html; charset=us-ascii
    Content-Transfer-Encoding: quoted-printable
    X-Originating-IP: []
    X-ClientProxiedBy: VI1PR0102CA0020.eurprd01.prod.exchangelabs.com
     (2603:10a6:802::33) To AM5PR1001MB1058.EURPRD10.PROD.OUTLOOK.COM
    Return-Path: no-reply<at>mydomain.com

    Tuesday, June 27, 2017 5:11 PM
  • And ipwhois results for - Geo Information
    IP Address
    Location     NL NL, Netherlands
    City     Amsterdam, 07 1091
    Organization     Microsoft Azure
    ISP     Microsoft Corporation
    AS Number     AS8075 Microsoft Corporation
    Latitude     52°35'00" North
    Longitude     4°91'67" East

    Tuesday, June 27, 2017 5:12 PM
  • It is MS address and Office 365 as SaaS is also hosted in same datacenters as Azure.

    Still this isn't problem with Azure but with Office 365 and you should contact O365 team for this.

    To verify, try sending mail to same address using same account with OWA or Outlook, you shoud get same report.

    Mustafa Toroman, Azure MVP

    • Proposed as answer by rnihad Tuesday, July 18, 2017 2:49 PM
    Tuesday, June 27, 2017 6:56 PM
  • I've sent some e-mails via online outlook and they have always reached recipients. It looks like different IP is used in that case.
    Tuesday, July 4, 2017 8:05 AM