SMTP server error: User is locked by your organization's security defaults policy
ERROR
SMTP server error: 5.7.57 Client not authenticated to send mail.Error: 535 5.7.139 Authentication unsuccessful, user is locked by your organization's security defaults policy.
Meaning:
Your Office 365 account (info@example.com
) is blocked from using SMTP AUTH due to Security Defaults or Conditional Access policies in your Microsoft 365 tenant.
Steps to Fix the Issue
Option 1: Disable Security Defaults (Tenant Level)
Log in to the Microsoft Entra (Azure AD) Portal: https://entra.microsoft.com/
Go to:
Identity
→Overview
→ PropertiesScroll to bottom, and look for: "Security defaults" → Set to "No"
Save changes.
This disables strict security defaults and allows SMTP login using username/password.
Option 2: Enable SMTP AUTH for the Specific Mailbox
Go to: https://admin.microsoft.com
Navigate to:
Users
→Active Users
→ clickinfo@extrakamai.com
In the right pane, click Mail → Manage email apps
Ensure "Authenticated SMTP" is enabled
REFERENCES
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