Microsoft 550 SC-001: rejected for policy reasons
Microsoft / Outlookpolicy_blockaction: review
550 SC-001 is Outlook.com refusing a message outright. Microsoft attributes it either to content with spam-like characteristics or to the reputation of the sending address or domain, and does not say which.
SC-001 and SC-004 are both 550 and read the same in a log, but SC-004 names complaints and SC-001 does not. If you are getting SC-001 with clean complaint figures, look at the message rather than the address.
What it looks like in the log
550 SC-001 Mail rejected by Outlook.com for policy reasonsWhy it happens
- Content that resembles mail Microsoft already filters, which can be a link, an attachment type, or a template shared with a worse sender.
- The address or domain carrying reputation that has not recovered.
What to do
- Check whether it is every message or one campaign. One campaign points at content; everything points at reputation.
- Audit the sending domain's authentication before assuming content: a policy refusal on an unauthenticated domain is usually the authentication.
- Enrol in SNDS to see what Microsoft thinks of the address.
Related
Domain check audits the sending domain's authentication, which is what a policy refusal usually turns out to be. Open domain check