Multiple copies of emails sent to recipients via SMTP


I use gmail to send e-mails via my office365 account. Since approximately 2 weeks ago, an issue started arising with multiple copies sent to recipients when more than one recipient is listed in the "to" box. The issue has been documented by several gmail users in the same situation and it has been attributed to a faulty SMTP on the office365 side:!msg/gmail/Or2-7uSwH6Y/nK9ZWItlAQAJ

Could you please advise how to solve this issue?



Question Info

Last updated February 17, 2020 Views 3,209 Applies to:

Hi All,

This issue was posted to the Service Health Dashboard (SHD) as incident EX149947 starting at Oct 3 2018 2:16:09 UTC. The user experience of this incident is: Users may notice duplicate emails from Microsoft 365 users or devices that utilize SMTP client submission. A suggested workaround is: we recommend users and admins leverage Option 2 or Option 3 within the KB article if they’re seeing duplicate copies:

Tenant administrators can view current information and updates on SHD at the link here

For affected customers to easily identify the information here, this thread will be closed.

​We will update to the primary thread below once the issue is resolved or you can obtain the most recent information from SHD.

Best Regards,


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