Land in the inbox.Not spam.
SPF, DKIM or DMARC misconfigured, and even great email goes to spam. This is five no-dependency Python scripts + a guide that find every controllable cause of filtering — and print the exact fix. Run it in 15 minutes.
Guess why you're in spam. Run the check. Get the fix.
-all — add: v=spf1 include:_spf… -allFIX01 / Why pay?
There are free SPF checkers online. So why buy this?
Because a browser checker tells you something's wrong — it doesn't print the fix, doesn't warm up a domain, doesn't screen your draft, and doesn't run itself every week. This toolkit finds the problem, gives you the exact solution, and drops into your own automation.
One domain, one time
Web checkers are a manual, one-off lookup. Deliverability isn't one-time — you re-check it every time DNS or sending volume changes.
Finds it, won't fix it
"DMARC: not found." Great — now which record, exactly? These scripts print the exact line to paste, for every failure.
No warmup plan
Send too much too fast on a fresh domain and you torch its reputation. A checker won't build you a ramp; this exports one as a CSV.
No preflight on your draft
Spam-trigger words, a bad text/HTML ratio, bare links — all get mail filtered. Nothing online checks your actual draft before you send.
Won't run in cron or CI
Exit codes matter. These return 0 clean / 1 needs-fixing, so a check can gate every campaign automatically.
No order, no reasoning
Authenticate, warm up, clean, then send — most people do it backwards. The guide explains the order that actually matters.
This toolkit is the fix: five scripts that find the problem and print the exact solution, run on your own machine, drop into cron or CI, plus a guide that explains the reasoning behind all of it.
02 / Contents
Everything in the download, listed before you buy.
- ✓5 Python scripts, zero dependencies
check_dns, blocklist_check, warmup_schedule, preflight_check and classify_bounce — stock Python 3.9+, nothing to pip install.
- ✓The deliverability guide
The reasoning behind every check: what to fix, in what order, and why authentication comes before volume.
- ✓DNS record templates — 8 providers
Copy-paste SPF, DKIM and DMARC records for the major mailbox and sending providers.
- ✓Cold-email sequence + suppression SQL
A ready 4-step sequence and the SQL for a proper suppression list, so hard bounces never get mailed twice.
- ✓Free updates for life
Come back to your download link any time — every future update is included.
03 / The scripts
Five scripts. Each finds a problem and prints the fix.
Run them in order or drop them into cron. Every script exits 0 when clean and 1 when something needs fixing — so it slots straight into CI.
SPF, DKIM, DMARC and MX in one pass — with the exact record to add for each failure.
Why it matters: the #1 controllable reason good mail is filtered.
Checks the DNSBLs that actually affect inbox placement — not the hundreds that don't.
Why it matters: know you're listed before the recipient's server does.
Generates a sending ramp from N to M per day and exports it to CSV.
Why it matters: volume too fast burns a fresh domain's reputation.
Screens a draft for the things that get mail filtered — before you hit send.
Why it matters: catch spam-trigger words and bad ratios in advance.
Reads any bounce message and returns a HARD / SOFT / COMPLAINT verdict.
Why it matters: keep hard bounces off your list, automatically.
04 / Also inside
A guide and templates, not just scripts.
The scripts tell you what's wrong. The guide and templates tell you exactly what to do about it.
The reasoning behind every check — authentication, reputation, warmup, list hygiene and content — and the order to do them in.
So you understand it, not just run it.
Copy-paste SPF, DKIM and DMARC records for the major mailbox and sending providers — no guessing the syntax.
Paste, don't hand-write the records.
A ready 4-step cold-email sequence and the SQL for a proper suppression list, so hard bounces are never mailed again.
Clean sending from day one.
Everything runs on your machine. No account, no telemetry, no data leaves your infrastructure — the scripts read public DNS and your own files.
05 / The order that matters
Authenticate. Warm up. Clean. Send.
Authenticate
Run check_dns.py and fix every FAIL it prints — SPF, DKIM, DMARC. Nothing else matters until these pass.
Warm up
Generate a ramp with warmup_schedule.py and follow the CSV. Reputation is earned slowly and lost fast.
Clean & send
Preflight each draft, check blocklists, and classify every bounce so your list stays clean campaign after campaign.
Most people do it backwards — blast volume first, then wonder why they're in spam. Authentication first, reputation second, volume last.
06 / Audience
Built for anyone who sends email that has to arrive.
Cold-outreach senders
Agencies and founders running outbound. Warmup, authentication and bounce hygiene decide whether you're ever seen.
SaaS & developers
Transactional email — receipts, resets, alerts — that has to land. Drop the checks into CI so a bad deploy can't break delivery.
Newsletter operators
Keep your list clean and your ratios right, and stay out of the promotions tab and the spam folder.
Freelancers & agencies
Set up deliverability for clients in an afternoon — unlimited domains on one licence.
07 / Fit check
What this toolkit is not.
Worth being explicit, so you buy the right thing:
- ✕Not a sending platform — it makes sure what you send arrives, it doesn't send it
- ✕Not a warmup service — it builds the schedule; you send on your own system
- ✕Not a guarantee of inbox placement — no tool can promise that; it removes the controllable causes of filtering
- ✕Not resellable as files — use it on unlimited domains, but don't repackage it
It is five scripts and a guide that remove the known, controllable reasons good email gets filtered.
08 / Requirements
What you need before you start.
pip install.09 / Ownership
You buy it once. You own the files.
✓ What you may do
- ✓Use the scripts and templates for your own business and for unlimited client projects
- ✓Run them on any number of domains and servers
- ✓Modify them and integrate them into your own systems and CI
- ✓Use the guide and templates with your clients
✕ What you may not do
- ✕Resell or redistribute the files themselves
- ✕Publish them publicly, in whole or in substantial part
- ✕Bundle them into another product for sale
The full file list, real output, requirements and a whole "what this is not" section are published above — so you know exactly what you're getting before you buy.
Email Deliverability Toolkit
one-time purchase · no subscription
- ✓5 no-dependency Python scripts (DNS, blocklists, warmup, preflight, bounces)
- ✓The deliverability guide — the reasoning and the order
- ✓DNS templates for 8 providers + sequence + suppression SQL
- ✓Commercial licence — unlimited domains
- ✓Free updates for life
- ✓Instant download — no account, no telemetry
10 / Questions
Answers before you ask.
Do I need to install anything? +
No. Everything runs on stock Python 3.9+, the version already on macOS and Linux. The DNS scripts use dig/nslookup if dnspython isn't present — so there's nothing to pip install.
Will this guarantee I reach the inbox? +
No honest tool can — receivers make their own call. What this does is remove the known, controllable causes of filtering: authentication, reputation, blocklists, list hygiene and content. That's the part you control.
Does it work for cold outreach? +
Yes — that's a primary use case. Domain warmup, authentication and bounce hygiene matter most there. Note that bulk-email law differs by country (CAN-SPAM, GDPR/PECR, CASL); the toolkit doesn't replace checking your legal obligations.
Are my credentials or data stored anywhere? +
No. The scripts read public DNS records and your own local files. Nothing is uploaded, there's no account, and no telemetry.
Can I use it for client work? +
Yes — the licence covers your own business and unlimited paid client work, on any number of domains. You just can't resell or redistribute the files themselves.
What do I receive after payment? +
Access to the download: the five scripts, the guide, the templates, START-HERE, licence and changelog. Start with START-HERE.md — it's your 15-minute setup.
Which script should I run first? +
check_dns.py on your sending domain. Fix anything it marks FAIL before you send a single campaign — authentication first, everything else second.
11 / Ready
Stop guessing. Run the check, get the fix.
Five scripts and a guide that get your email into the inbox — on unlimited domains.