My outgoing mail has been marked as spam using mail merge, how to fix. I am a paid subscriber

Dr. Pushpendra N Renjen 0 Reputation points
2026-10-16T03:47:31.2966667+00:00

Your message wasn't delivered. Please try resending the message.

Diagnostic information for administrators:

Generating server: BLAPR19MB4610.namprd19.prod.outlook.com

******@gmail.com Remote server returned '554 5.7.0 < #5.7.520 smtp;550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)>'

Original message headers:

Received: from MN2PR19MB2814.namprd19.prod.outlook.com (2603:10b6:208:ec::11)
 by BLAPR19MB4610.namprd19.prod.outlook.com (2603:10b6:208:291::21) with
 Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.522.13; Fri, 16 Oct
 2026 03:36:41 +0000
Received: from MN2PR19MB2814.namprd19.prod.outlook.com
 ([fe80::d622:8d3a:9ee8:aba5]) by MN2PR19MB2814.namprd19.prod.outlook.com
 ([fe80::d622:8d3a:9ee8:aba5%4]) with mapi id 15.21.0496.021; Fri, 16 Oct 2026
 03:36:41 +0000
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: base64

From: "Dr. Pushpendra N Renjen" <******@hotmail.com>
To: "******@gmail.com" <******@gmail.com>
Subject: EC Candidate for IAN Election 2026 
Thread-Topic: EC Candidate for IAN Election 2026 
Thread-Index: Ad1dGKvtLhQ6XeDUSOOEe1rlZTWPtg==
Date: Fri, 16 Oct 2026 03:36:41 +0000
Message-ID: <******@MN2PR19MB2814.namprd19.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator: <******@MN2PR19MB2814.namprd19.prod.outlook.com>
MIME-Version: 1.0
X-MS-PublicTrafficType: Email
X-MS-TrafficTypeDiagnostic: MN2PR19MB2814:EE_|BLAPR19MB4610:EE_
Return-Path: ******@hotmail.com
X-MS-Office365-Filtering-Correlation-Id: ce3a7ce9-e392-44d7-7458-08df2b36b152
X-MS-Exchange-SLBlob-MailProps:
Outlook | Web | Outlook.com | Account management, security, and privacy
0 comments

1 answer

Sort by: Oldest
Most helpful Newest Oldest

  1. AI answer

    2026-10-16T03:47:52.83+00:00

    554 5.7.520 ... Message blocked because it contains content identified as spam. AS(4810) means the message content was identified as spam by the mail filter.

    For an Outlook.com/Hotmail mail merge scenario, use this path:

    1. Send a plain-text test message first Remove anything that looks risky and send a simple message with no attachment, no images, and no links. If that succeeds, the block is being triggered by the message content rather than the account itself.
    2. Review the message body for common spam triggers Keep the message clean and direct. Remove or reduce:
      • repeated or highly similar mail-merge content
      • large attachments
      • shortened or multiple links
      • excessive promotional wording or heavy formatting
    3. Avoid TNEF/winmail.dat formatting The headers show Content-Type: application/ms-tnef; name="winmail.dat". That format can make messages less compatible with some recipients. Send using standard HTML or plain text instead of Rich Text/TNEF, then test again.
    4. Add content back gradually If the plain-text test works, reintroduce content one change at a time:
      • first the normal text
      • then one link if needed
      • then any attachment This isolates the exact element causing the spam verdict.
    5. Check for suspicious account activity Review recent sent mail for anything unfamiliar. If there are unexpected messages, secure the account before sending more.
    6. If sending to many recipients, reduce volume and pace Mail-merge patterns can resemble bulk mail. Send in smaller batches and space messages out.
    7. If the issue continues, use sender support Outlook.com provides sender tools and a deliverability support form for issues affecting @outlook.com, @hotmail.com, @live.com, and @msn.com senders:

    Also verify the sending system is not advertising a private, non-routable IP in reverse DNS, because Outlook.com may reject mail from senders that fail reverse-DNS checks.

    AI-generated content may be incorrect. Read our transparency notes for more information.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.