emails that i send with bcc are getting bounced back, using a gmail account via outlook?

Question

emails that i send with bcc are getting bounced back, using a gmail account via outlook?

DAVID GOBBERDIEL 40

This is a daily email i send to 50 people via bcc via outlook with a gmail email...

response was : Message rejected. For more information, go to https://support.google.com/mail/answer/69585

1 of 2 attachments in bounce back message: Reporting-MTA: dns; googlemail.com

Received-From-MTA: dns; ******@gmail.com

Arrival-Date: Thu, 18 Dec 2025 08:41:41 -0800 (PST)

X-Original-Message-ID: 015901dc703d$30848760$918d9620$@gmail.com

Final-Recipient: rfc822; ******@iastate.edu

Action: failed

Status: 5.7.1

Diagnostic-Code: smtp; Message rejected. For more information, go to https://support.google.com/mail/answer/69585

Last-Attempt-Date: Thu, 18 Dec 2025 08:41:44 -0800 (PST)

2 0f 2 attachments in bounce back email: X-Gm-Gg: AY/fxX4QRzpz72o9AlI8kqo9O4A/myQLhr+Dxn5Q428SmS7HlmDdLx/RhWteuCqyn88

sXjhESaAM2yGdzRhY4WwiWATTcUrec+1wcalbZbQziV703Mv6JmXPSdU4ayDBA/FxbWLxjNiKAf

y1eKBUH3DPrrCTiKkX2FWg56xpYky5Vh9SCVBcuiPRl/rhwTtGt0Tt7T9av7luU2i0sMyeYTPhz

acJnr7bFmj/OL/qSJteizDaV/tx3u0ey842B+RlZ+YeMdJmhuS4nJCsS7ppPL831PW7YzQLqOrx

ld8oKlvBse1QNreBZ8saJt0ouezCq/Ov9WUbIekBwPFUM/MRhSe0o4e3h0N4NCv541tZbdUrrJX

Nc4PeACNdfEi89BaTDJNFzn7OZgmfr+eUfpMARGlkTFU8knFV03drdRx0eknvk1CZb221rYM9yY

0Z/EuROX1i9BjZ5acTLMpQ0e8DIQNoIENzI4DYSzDDMHvV7MwCazX1l3ly

X-Google-Smtp-Source: AGHT+IHGryaatw9vawtXn8gC8vJ5K5nc80peRNn5uSg6Wv3zjR974+9EMChWzt+FiD2qAGnpG0tDpA==

X-Received: by 2002:a05:6a00:b60c:b0:7b9:7349:4f0f with SMTP id d2e1a72fcca58-7ff61599e45mr55556b3a.0.1766076103036;

    Thu, 18 Dec 2025 08:41:43 -0800 (PST)

Return-Path: ******@gmail.com

Received: from DCGDT (75-164-229-3.ptld.qwest.net. [75.164.229.3])

    by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7fe1194c67csm3120329b3a.1.2025.12.18.08.41.40

    (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128);

    Thu, 18 Dec 2025 08:41:41 -0800 (PST)

From: ******@gmail.com

To: ******@gmail.com

Subject: up she rises edition... Gambling Vs. Investing, Sector and Big Tech Correlations

Date: Thu, 18 Dec 2025 08:41:40 -0800

Message-ID: 015901dc703d$30848760$918d9620$@gmail.com

MIME-Version: 1.0

Content-Type: multipart/related;

boundary="----=_NextPart_000_015A_01DC6FFA.22687350"

X-Mailer: Microsoft Outlook 16.0

Thread-Index: AdxwPPtH+uM/LBB1Q9W3ukyxnf4Nqg==

Content-Language: en-us

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Answer 1

EmilyS726 257.3K Independent Advisor

Hello

What you’re seeing is a Gmail spam / abuse enforcement, not a technical send failure in Outlook.

Error 5.7.1 from Gmail indicates the message was rejected due to policy enforcement, most commonly spam or bulk sending limits.

The linked Google page confirms the usual triggers:

https://support.google.com/mail/answer/69585

I am afraid you would have to work with Google support on this.

DAVID GOBBERDIEL 40 Reputation points

2025-12-18T19:14:35.2533333+00:00

Thanks... I'm seeing that as well but the amount I send is perhaps one or two a day to a bcc with 50 addresses on it, appears well below gmail's threshold as I read it. This all started yesterday after several years of like traffic. confusing at best... I'll keep digging with gmail. best to you.
EmilyS726 257.3K Reputation points Independent Advisor

2025-12-18T19:16:47.6833333+00:00

While I cannot speak for Google, but sending limit is quite a dynmaic thing, works like credit score and is according to your usage history. At least that's how it works with Microsoft email addresses. It can be the case with Google too.

Answer 2

The bounce-back message you received indicates that your email was rejected with a status code of 5.7.1. This typically means that the message was blocked due to policy reasons, which can occur when sending emails to multiple recipients using BCC from a Gmail account. Here are a few potential reasons and solutions:

Recipient's Block List: The recipient you are trying to send to may have blocked your email address. You can check with the recipient to ensure your email is not on their block list.
Gmail Sending Limits: Gmail has limits on the number of recipients you can send to in a single email. If you exceed these limits, your emails may be rejected. For Gmail, the limit is generally around 500 recipients per day for regular accounts. Consider splitting your emails into smaller groups.
Email Content: Sometimes, the content of the email can trigger spam filters. Ensure that your email does not contain any content that may be flagged as spam.
Use of BCC: While BCC is a useful feature, some email providers may flag emails sent to many BCC recipients as spam. You might want to consider using a mailing list service that is designed for bulk emailing.
Check Email Settings: Ensure that your Gmail settings in Outlook are correctly configured. Sometimes, incorrect settings can lead to delivery issues.

If the issue persists, you may want to refer to the link provided in the bounce-back message for more detailed information on troubleshooting Gmail errors.