Symptoms#
- Messages landing in spam despite previously good placement
- Bounces mentioning policy, authentication, or reputation
- Provider dashboards showing a drop in reputation or authentication pass rate
Diagnosis steps#
- Confirm the configuration is live: query DNS from an external resolver and check the sending platform's settings page.
- Send to a seed mailbox and read the full headers, especially Authentication-Results.
- Compare the domains in From, Return-Path, and DKIM d= for alignment.
- Check provider dashboards (Google Postmaster Tools, Microsoft SNDS) for reputation and error rates.
- Review recent changes: new vendors, DNS edits, list imports, volume spikes.
Likely causes#
- Unsubscribe pages that ask 'are you sure' with a hidden confirm button.
- Continuing sequences from a different tool after an opt-out in another.
Fix and re-verify#
- Include a visible unsubscribe link in every marketing message.
- Add List-Unsubscribe and List-Unsubscribe-Post headers so providers show a native unsubscribe button.
- Process opt-outs immediately; the legal maximum is 10 business days in the US, but providers expect 2 days.
- Never require login or more than one click to unsubscribe.
Frequently asked questions#
What is one-click unsubscribe?
An RFC 8058 header pair that lets the mailbox provider send a POST to your endpoint when a user clicks Unsubscribe in the client, with no landing page.