ONLINE
Deliverability Letter

450 4.7.1

SFR_IN_101 Spam Complaints

Spam Detection

SFR detected too many spam complaints and blocked the IP for two hours.

SFR_IN_101 is triggered when subscribers mark excessive messages as spam. The block affects all SFR brands (sfr.fr, neuf.fr, numericable.fr).

Severity

ERROR

Provider

SFR

Reference

SFR_IN_101

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.

  • Pause SFR traffic and remove unengaged or purchased lists immediately.
  • Review Signal Spam feedback loop reports for complaint trends.
  • Slow the send rate and resume with high-engagement cohorts first.
  • Audit creative, frequency, and consent sources before ramping back up.

Still experiencing SFR delivery issues?

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