Error -17099 or -3253 when trying to send an email with an attachment

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Applies To

Outlook for Microsoft 365 for Mac Outlook 2019 for Mac

Last Updated: July 23, 2021

ISSUE

When sending an email with an attachment, you receive an error -17099 or -3253 and the email fails to send.

STATUS: FIXED

This issue was introduced in the Vulnerability Protection module of Norton Security for Mac version 8.6.3 or newer. Norton has released a hotfix to resolve the issue.

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