Diagnose before you buy.

Blacklist Checker ↗

Check if your domain or IP is listed on 20+ major email blacklists in seconds.

Use when Replies stopped overnight

If it fails Delisting takes days and often does not stick. A prewarmed .com ships today.

Bounce Analyzer ↗

Paste bounce messages, get the root cause in plain English plus a pause-or-continue verdict.

Use when Bounces spiked mid-campaign

If it fails A reputation block disguised as a soft bounce means stop sending now.

Deliverability Checker ↗

Grade your domain A to F across SPF, DKIM, DMARC, MX, blacklists and domain age.

Use when Opens fell off a cliff

If it fails Under 80% placement? Adding volume to a damaged domain makes it worse.

DNS Checker ↗

Query MX, TXT, CNAME, A and all other DNS record types for any domain.

Use when New domain or a migration

If it fails MX wrong means replies vanish. Fix it or replace the domain.

Domain Expiry Checker ↗

Monitor domain expiration dates and catch renewals before they lapse.

Use when You run a fleet and renewals are manual

If it fails An expired sending domain kills delivery and replies at once.

Google Domain Checker ↗

See if a domain is already tied to a Google Workspace account or clear for fresh inboxes.

Use when Account setup failed on a domain

If it fails Already linked to another Microsoft account. Use a clean prewarmed domain instead.

Header Analyzer ↗

Paste raw headers: SPF, DKIM, DMARC, alignment and hops explained in plain English.

Use when You need to know why one message failed

If it fails Authentication failing at the receiver is an infrastructure problem.

Outlook SCL Analyzer ↗

Paste Outlook headers and find out exactly why the message went to Junk.

Use when Outlook is junking you

If it fails Microsoft-heavy list? Send from Microsoft infrastructure.

SURBL & Spamhaus DBL Checker ↗

Bulk-check domains against the SURBL and Spamhaus DBL URI blacklists.

Use when Sending domain is clean but mail still filters

If it fails Your tracking domain or links are listed, not your sender.

BIMI Checker ↗

Validate your brand logo record, SVG, VMC and the DMARC enforcement Gmail requires.

Use when Checking enforcement posture

CNAME Checker ↗

Follow the full CNAME chain and catch the mistakes that break a cold email tracking domain.

Use when Tracking links look wrong

If it fails A shared tracking host pools reputation with every other sender on it.

DKIM Checker ↗

Auto-scan 26 common selectors and validate your DKIM signing key strength.

Use when You do not know which selector is live

If it fails Published but not signing is the most common silent failure.

DMARC Checker ↗

Validate and analyse your DMARC record, policy, tags and verdicts explained.

Use when Before moving policy to quarantine or reject

If it fails Every prewarmed domain ships with DMARC already set.

MTA-STS Checker ↗

Validate your _mta-sts record and policy file: enforce mode, MX patterns and TLS-RPT.

Use when Hardening inbound for replies

Nameserver Checker ↗

One domain or a whole CSV: get NS records and the DNS provider behind every domain.

Use when Auditing who controls a fleet

If it fails Domains on a vendor nameserver are theirs, not yours.

Record Generator ↗

Build correct SPF, DKIM and DMARC records, with ready-made settings for Google, Microsoft and the big sending tools.

Use when Standing up a new sending domain

If it fails Copied records carry includes you do not use. Generate them.

SPF Checker & Generator ↗

Look up existing SPF records or build a new one, with recursive lookup counting.

Use when Setting up or auditing a domain

If it fails Over ten lookups is a PermError, and a PermError is a failure.

CSV List Cleaner ↗

Dedupe and scrub lead lists entirely in your browser, nothing gets uploaded.

Use when A list arrived messy

CSV Combiner ↗

Merge multiple lead lists into one, matching headers and deduping emails.

Use when Merging lists from several sources

Email Verifier ↗

SMTP-level mailbox verification with catch-all detection.

Use when Before a list touches a domain

Sequencer CSV Converter ↗

Convert lead CSVs between Instantly, Smartlead and Email Bison formats.

Use when Moving between sequencers

Suppression Checker ↗

Check any list against customers, unsubscribes and previously contacted companies.

Use when Before every launch

Waterfall Calculator ↗

Find the cheapest verifier order and your true cost per usable email.

Use when Verification spend is creeping up

Inbox Previewer ↗

See your sender, subject and snippet exactly as Gmail and Outlook render them.

Use when Finalising sender name and subject

Pre-Send Checker ↗

Catch broken merge tags, dupes and spintax errors, and forecast send volume.

Use when Right before a sequence goes live

Spam Checker ↗

Scan your subject and body for 200+ weighted spam triggers and formatting red flags.

Use when Writing or reviewing copy

Spintax & Liquid Tester ↗

Preview every spintax variation and personalization variable before sending.

Use when Using spintax or Liquid

Unsubscribe Generator ↗

CAN-SPAM and GDPR compliant opt-out footers in plain text and HTML.

Use when Building the footer

ESP Segmentation & Mailbox Calculator ↗

Split your list by Google, Microsoft and gateway inboxes, then get told how many mailboxes to buy.

Use when You do not know your recipient mix

If it fails A Microsoft-heavy list wants Microsoft infrastructure.

Domain & Inbox Planner ↗

Target volume in, exact domains and inboxes needed out, with a safe ramp-up plan.

Use when Sizing a new campaign or client

Inbox Rotation Planner ↗

Split your fleet into rotating batches with a schedule, no burned inboxes.

Use when Running more inboxes than one pod

How Many Inboxes Do You Need?

The four-step sizing arithmetic, plus packs vs tenant. Runs at Warm Inboxes.

Use when Sizing a campaign or a client

Warmup Tax Calculator

What running your own 51-day cycle costs, per year.

Use when Deciding whether to warm your own