Bounce code RL000001
What the knowledge base's own tables say about this code, and which articles say it — a description of the reply, never a placement prediction.
This line comes from a knowledge base article on Comcast, not on the standard.
- Basis
- Sender reputation from SenderScore, plus authentication of the sending server, however many domains send from it
From Comcast / Xfinity — Postmaster: Error Codes, Rate Limits, Unblocking · Rate limiting (RL codes)