Audit Email Deliverability: SPF DKIM DMARC MX + Gmail & Outlook

Audit SPF, DKIM, DMARC & MX—and verify inbox placement in Gmail & Outlook

This n8n workflow checks your sending domain’s email authentication (SPF, DKIM, DMARC, and MX) using Google DNS-over-HTTPS, then validates real deliverability by reading recent messages in connected Gmail and Outlook mailboxes—finally sending you a ranked fix report via Gmail.

What this workflow does

• Manual trigger: Runs when you start the workflow manually.
• DNS authentication audit: Builds DNS queries for SPF, DMARC, MX, and a list of common DKIM selectors, then resolves them using Google DNS-over-HTTPS.
• Score and flag issues: Grades your configuration by analyzing returned DNS records and flags problems such as missing records, unsafe SPF policy, or excessive SPF lookup count.
• Gmail placement review: Reads recent messages from Gmail (including Spam and Trash) sent from the configured sender address and summarizes where they landed across categories like Primary, Promotions, and other sections.
• Outlook placement review: Reads recent messages from Microsoft Outlook Inbox and Junk, summarizing placement across Focused, Other, and Junk.
• AI-generated deliverability recommendations: Combines DNS results and mailbox placement signals, then asks Anthropic Claude to explain findings and rank fixes by expected impact.
• Email report: Compiles a plain-text deliverability report and emails it via Gmail.

Use cases

• Validate a new sending domain’s SPF/DKIM/DMARC setup before launching campaigns
• Investigate sudden inboxing problems by correlating DNS misconfigurations with Gmail/Outlook placement
• Ongoing deliverability monitoring for SaaS and transactional email operators

Technical details

• n8n nodes/approach: code, gmail, merge, sticky note, http request, manual trigger
• DNS lookup: Google DNS-over-HTTPS
• AI: Calls the Anthropic Messages API using ANTHROPIC_API_KEY (environment variable)
• Configurable inputs: DOMAIN, DKIM selector list (if needed), optionally SENDER_ADDRESS, LOOKBACK_DAYS, and MAX_MESSAGES