Full email compatibility preview, transforms HTML for 21 email clients (Gmail, Outlook, Apple Mail, Yahoo, Samsung, Thunderbird, HEY, Proton Mail, AOL, Fastmail, Superhuman), analyzes CSS, generates scores, simulates dark mode, checks inbox preview and email size.
Quick CSS compatibility analysis, returns per-client scores and one finding per problem, listing the clients it affects. For HTML input each finding carries loc (line, column, offset) and alsoAtLines, so you can edit the exact source. Narrow with clients, or pass detail:'full' for the per-client breakdown with fix snippets. Use audit_email for a full quality report (spam, links, a11y, images, etc.).
Comprehensive email quality audit: CSS compatibility, spam scoring, link validation, accessibility, images, inbox preview, size (Gmail clipping), template variables, content overflow, visual fallbacks, dark-mode and mobile text contrast, design consistency, and structural faults in Outlook-only VML (which lives inside conditional comments and is invisible to every other check). For HTML input, findings tied to a specific element carry loc (line, column, offset) so you can edit the exact source. Compatibility is collapsed to one finding per problem listing the clients it affects; pass detail:'full' for the per-client breakdown with fix snippets. Use skip to omit checks and clients to narrow which clients are reported.
Generate a structured fix prompt for email compatibility issues. Returns markdown with the original code, detected issues (CSS or structural), fix snippets, and format-specific instructions. Use after preview_email or analyze_email.
List every supported email client with IDs, names, engines, and dark mode support.
Compare two email HTML versions, shows score changes, fixed issues, and newly introduced issues per client. Use after making fixes to verify improvements.
Check email deliverability for a domain: SPF, DKIM, DMARC, MX, and BIMI records. Returns a score (0-100) and actionable issues. Uses DNS lookups (no API key needed).
Capture real email screenshots across 21 clients (Gmail, Outlook, Apple Mail, etc.) with light and dark mode variants. Screenshots are rendered in real browsers and hosted on CDN. Requires EMAILENS_API_KEY env var — free plan at emailens.dev?ref=mcp.
Create a shareable link for an email preview. Recipients see the full analysis without needing an account. Requires EMAILENS_API_KEY env var and Dev plan ($9/mo).