Orange
Orange is an internet service provider that provides free email accounts to both its customers and registered non-customers, headquartered in Paris. Eurproean receivers tend to have high expectations for GDPR legal complaince, so after you've ensured the mail is legitimate and following all best practices, you can typically report false-positive blocks and spam filtering to Orange's "Abuse Cell" team to investigate.
5 responses across 3 reply codes
SMTP 501
1 responses
SMTP 550
3 responses
5.2.0
Orange rejected the message. Review content, authentication, and recent complaint rates before retrying.
5.1.1
Orange says at least one recipient is invalid. Fix or remove the bad address, then resend.
4.0.0
Orange blocked your IP through Cloudmark Sender Intelligence. Request delisting, then retry after the block clears.
SMTP 552
1 responses
Response catalog adapted from the MIT-licensed SMTP Field Manual by ActiveCampaign / Postmark.