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Deliverability Letter

450 4.7.1

SFR_IN_102 Virus or Malware Detected

Security

SFR found malware or dangerous attachments and blocked the IP for two hours.

If your outbound stream includes executable attachments or infected links, SFR issues SFR_IN_102 and suspends the connection.

Severity

CRITICAL

Provider

SFR

Reference

SFR_IN_102

Last Reviewed

2025-06-01

How to Fix 450 4.7.1

Follow these steps to resolve this SFR SMTP error and restore normal delivery.

  • Scan outbound messages with multiple antivirus engines before sending.
  • Disable file types that SFR routinely blocks (EXE, SCR, certain ZIP archives).
  • Investigate compromised accounts or relays immediately.
  • Rebuild trust with a gradual ramp once the issue is resolved.

Still experiencing SFR delivery issues?

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