A Deliverability Audit You Can Run in an Afternoon

A founder messaged me at the end of a campaign that had quietly failed. Three weeks of work, a list he trusted, replies he never got. He wanted to know which agency to hire to fix his “messaging.” I asked him to do one thing first: send a test email to a personal Gmail account and tell me where it landed.

It landed in Promotions. The next one went to spam.

He didn’t have a messaging problem. He had a problem he’d never looked at, because nothing about it was visible from inside his sending tool. So we ran an audit. Not a rewrite — an audit. It took an afternoon, and by the end he knew exactly what was broken and in what order to fix it.

You can run the same audit yourself. You don’t need a vendor, a contract, or a single new tool you have to learn. You need a few free checkers, your DNS records, and a quiet two hours. Here is the order I work in.

Start where the message ends

Most people audit email from the outside in — they read their own copy and ask what’s wrong with it. I work from the destination backward. The first question isn’t “is this email good?” It’s “does this email arrive, and where?”

Send a plain test message to a fresh Gmail address, an Outlook address, and a Yahoo address. Use your real sending setup, not the “send test” button in your tool, which often routes through a different path. Then look at where each one landed: Primary, Promotions, spam, or nowhere at all. Three providers, three placements. That spread is your first diagnostic. If one provider buries you and another doesn’t, the problem is reputation, not content.

Read the headers, not the copy

Open the message you received and view the original — in Gmail it’s “Show original.” You’re looking for three lines: SPF, DKIM, DMARC. Each should say PASS. Most broken sending setups fail at least one of these without the sender ever knowing.

SPF declares which servers may send for your domain. DKIM signs each message so it can’t be altered in transit. DMARC tells the receiver what to do when the first two disagree. A green pass on all three is not a nice-to-have. It is the difference between a receiver trusting your domain and guessing about it. If any line says FAIL, SOFTFAIL, or NONE, you’ve found your afternoon’s work.

Check the records at the source

Now go to your DNS and read the records directly. A free tool like MXToolbox or Google’s Dig will show you what’s actually published. Three things go wrong here more than anything else:

An SPF record with more than ten DNS lookups — which silently breaks once you exceed the limit, no warning, no error. A DKIM key that was generated years ago and never rotated. And a DMARC policy set to p=none, which means you are watching failures scroll past and doing nothing about them. p=none is not protection. It’s a window.

This is the heart of the audit, and it’s also where most people stop too early. A record that exists is not a record that works. Read the values, not just the presence.

Look up your reputation

You can’t see your sender reputation from inside your inbox, but the receiving world can see it perfectly. Check whether your domain or sending IP sits on a public blocklist — Spamhaus and a multi-RBL checker take thirty seconds. Then look at Google Postmaster Tools if you send any volume to Gmail; it shows your domain reputation as Google itself scores it.

A clean record here means the foundation is sound and you can look upstream at content and targeting. A listing means stop — nothing you write will land until the listing clears, and that takes patience, not persuasion.

Audit the list before you blame the market

The last pass is the one founders resist, because it implicates a decision they already made. Run a sample of your list through a verification service. Dead addresses, role accounts like info@ and sales@, and spam traps don’t just fail to convert — each one actively damages the reputation you just measured. A list you bought and never cleaned is not a list. It’s a liability that degrades every send after it.

What the afternoon gives you

By the end you have a short, ordered map: where mail lands, which authentication passes, what your records actually say, whether you’re listed, and how clean your list is. Not opinions — readings. Most people discover the bottleneck is in the first three steps, long before any word of copy matters.

This is the reframe worth keeping. Deliverability is not a writing problem you solve with a better sentence. It is a systems problem you diagnose with a sequence of checks. The copy is the last thing to fix, not the first — because the best email in the world is invisible if it never arrives.

An afternoon is enough to know. The fixing comes after, and it’s far easier when you know exactly what you’re fixing.

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Related

• Service: Email Infrastructure & Deliverability — DNS authentication, domain rotation, and deliverability systems that land in the inbox.
• Article: Why Your Cold Emails Are Going to Spam — The infrastructure problems an audit surfaces, explained from the diagnosis side.
• Article: How Multi-Domain Outreach Actually Works — What you build once the audit tells you the foundation is sound.
• Deep Dive: Compliance as System Behavior — Why deliverability, like compliance, is system behavior upstream of the message — and why an audit reads the system, not the copy.

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Run the audit, fix the foundation, then write. If you’d rather have someone read the headers with you, start at ivanboban.com.