Cold Email Infrastructure Calculator by Recipient ESP

Other free deliverability tools

The rest of the toolkit, all free and all without an account.

• Blacklist Checker — Check if your domain or IP is listed on 20+ major email blacklists in seconds.
• Deliverability Checker — Grade your domain A to F across SPF, DKIM, DMARC, MX, blacklists and domain age.
• DMARC Checker — Validate and analyse your DMARC record, policy, tags and verdicts explained.
• SPF Checker & Generator — Look up existing SPF records or build a new one, with recursive lookup counting.
• DKIM Checker — Auto-scan 26 common selectors and validate your DKIM signing key strength.
• DNS Checker — Query MX, TXT, CNAME, A and all other DNS record types for any domain.
• Domain Expiry Checker — Monitor domain expiration dates and catch renewals before they lapse.
• Record Generator — Build correct SPF, DKIM and DMARC records with presets for every major ESP.
• ESP Segmentation & Mailbox Calculator — Split your list by Google, Microsoft and gateway inboxes, then get told how many mailboxes to buy.
• Nameserver Checker — One domain or a whole CSV: get NS records and the DNS provider behind every domain.
• SURBL Checker — Bulk-check domains against the SURBL URI blacklist.
• Spamhaus DBL Checker — Bulk Spamhaus Domain Block List lookups for your sending and link domains. Coming soon.
• Google Domain Checker — See if a domain is already tied to a Google Workspace account or clear for fresh inboxes.
• Email Verifier — SMTP-level mailbox verification with catch-all detection.
• Spam Checker — Scan your subject and body for 200+ weighted spam triggers and formatting red flags.
• CSV List Cleaner — Dedupe and scrub lead lists entirely in your browser, nothing gets uploaded.
• Spintax & Liquid Tester — Preview every spintax variation and personalization variable before sending.
• Domain & Inbox Planner — Target volume in, exact domains and inboxes needed out, with a safe ramp-up plan.
• Inbox Rotation Planner — Split your fleet into rotating batches with a schedule, no burned inboxes.
• Pre-Send Checker — Catch broken merge tags, dupes and spintax errors, and forecast send volume.
• Suppression Checker — Check any list against customers, unsubscribes and previously contacted companies.
• Bounce Analyzer — Paste bounce messages, get the root cause in plain English plus a pause-or-continue verdict.
• Outlook SCL Analyzer — Paste Outlook headers and find out exactly why the message went to Junk.
• Waterfall Calculator — Find the cheapest verifier order and your true cost per usable email.
• Sequencer CSV Converter — Convert lead CSVs between Instantly, Smartlead and Email Bison formats.
• CSV Combiner — Merge multiple lead lists into one, matching headers and deduping emails.
• Unsubscribe Generator — CAN-SPAM and GDPR compliant opt-out footers in plain text and HTML.
• Inbox Previewer — See your sender, subject and snippet exactly as Gmail and Outlook render them.
• Header Analyzer — Paste raw headers: SPF, DKIM, DMARC, alignment and hops explained in plain English.
• BIMI Checker — Validate your brand logo record, SVG, VMC and the DMARC enforcement Gmail requires.
• CNAME Checker — Follow the full CNAME chain and catch the mistakes that break a cold email tracking domain.
• MTA-STS Checker — Validate your _mta-sts record and policy file: enforce mode, MX patterns and TLS-RPT.