Deliverability monitoring

Core Telemetry Streams

flowchart LR
    A[Sending IPs / Domains] --> B[Recipient Mail Gateways]
    B -->|DMARC XML Reports| C[Aggregate Ingestion Service]
    B -->|Feedback Loops| D[Spam Complaint Telemetry]
    C --> E[Observability Dashboard & Alerts]
    D --> E

1. DMARC Aggregate (RUA) Analysis

Recipient mail servers generate daily XML reports summarizing every message received claiming to originate from your domain:

Source IP & Country: Identifies where the message originated.
Message Volume: Count of messages processed in that window.
SPF Evaluation: IP match result and alignment status.
DKIM Evaluation: Cryptographic verification status and selector alignment.
Disposition: Applied action (none, quarantine, reject).

Tools like Postmark DMARC, Valimail, or self-hosted Parsedmarc ingest these XML archives and produce actionable triage dashboards.

2. Mailbox Provider Telemetry

Direct feedback telemetry provided by major consumer inbox networks:

Provider	Tool	Key Metrics Monitored
Google	Google Postmaster Tools (GPT)	Domain reputation, IP reputation, spam rate (keep under 0.1%), SPF/DKIM/DMARC success rates, delivery errors.
Microsoft	Smart Network Data Services (SNDS)	Sending IP status, complaint rates, spam trap hits, filter results.
Yahoo / AOL	Complaint Feedback Loop (CFL)	Automated ARF reports when users click “Mark as Spam”.

3. Real-Time DNSBL & Blacklist Auditing

Monitor major Real-time Blackhole Lists (RBLs) and DNS Blocklists (DNSBLs):

Spamhaus (SBL, XBL, PBL, DBL): High severity. Immediate delivery failure across most enterprise and consumer mail servers.
Barracuda (BRBL): Widespread enterprise mail server usage.
SORBS & Invaluement: Common secondary enterprise filters.

Automate daily reverse DNSBL queries across sending IPs:

# Reverse IP lookup against Spamhaus Zen
dig +short 25.100.51.198.zen.spamhaus.org
# Returns 127.0.0.x if listed, empty if clean

Deliverability Health Checklist

Daily spam rate remains strictly below 0.1% (never sustained above 0.3%).
DMARC aggregate compliance rate above 99.5% on active transactional streams.
Automated alerts trigger on unexpected new sending IPs in aggregate reports.
Feedback Loop (FBL) complaints immediately unsubscribe or suppress recipient addresses.
DNSBL status tracked continuously via automated ping or monitoring agent.