OFR_101: sending IP listed by Spamhaus

What it means

Code 101 means Orange found your sending IP on a Spamhaus blocklist and refused the mail. Spamhaus runs several lists, covering spam sources, compromised machines and address ranges that should not send mail directly. Orange sends you to the Spamhaus lookup, check.spamhaus.org, which shows which list holds the IP, why, and how removal works for that list. The Orange table gives no other step for this code.

Common causes

• Spam or malware traffic from the IP was seen by Spamhaus.
• The IP belongs to a range Spamhaus lists, such as end-user or dynamic addresses.
• A previous user of the IP left a listing behind.

How to fix it

1. 01Look the IP up at check.spamhaus.org.
2. 02Fix the cause Spamhaus gives and follow its removal process.
3. 03Retry delivery after the listing is gone.

Sources

What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.

• Orange Postmaster Page (SMTP Delivery Guidelines and Error Codes)postmaster.orange.fr

Further reading

• Spamhaus ZEN in the blacklist wiki
• Blacklist checker