A deliverability audit answers one question: why is your email not reaching the inbox, and in what order should you fix it?
Done properly it costs $300 to $800, takes about a week, and ends with a ranked list rather than a report nobody reads. Here is what should be in it, and what the findings usually turn out to be.
What a real audit checks
| Check | What it looks for | Why it is usually the problem |
|---|---|---|
| Real placement | Where emails actually land in Gmail, Outlook, Yahoo accounts | Open rates lie; eyes on an inbox do not |
| Authentication | SPF, DKIM, DMARC passing on every sending domain | DKIM fails silently on a surprising share of "healthy" domains |
| Domain age and warmup | 30+ days old, warmed 21 to 30 days uninterrupted | Most burnt fleets launched too early |
| Bounce rate | Under 2% | Above that, reputation damage compounds quietly |
| Volume per inbox | 10 to 30 a day depending on fleet age | Ramping too fast looks like a spike, and a spike looks like spam |
| Blacklists | Domain and IP listings | Rarely the cause, always worth ruling out |
| Out-of-office rate | Above 2% means the calendar is wrong, not the campaign | Almost nobody checks this |
| List quality | Twenty random contacts, read by a human | Most underperforming lists are 30 to 40% wrong-fit |
The order matters as much as the checks. Most people start at the copy, which is the last place to look, and lose a month there. The full diagnostic sequence is in why your cold email lands in spam.
What audits usually find
After enough of these, the findings cluster. In rough order of frequency:
Authentication set but not working. The DNS records exist, the dashboard shows green, and DKIM is silently failing on a third of the domains because of one copy-paste error months ago.
Volume ramped faster than reputation. The tool allowed 50 a day, so 50 a day went out, on domains three weeks old.
The list decayed. Verified once, at build time, months ago. Lists decay around 2% a month, and the bounces have been quietly eroding sender reputation ever since.
Nothing is wrong at all. The campaign launched into August or late December, the out-of-office rate is 11%, and the only finding is a calendar.
What you can do yourself
Before paying anyone, an afternoon covers the first layer:
- Send from a sample of your domains to real Gmail, Outlook and Yahoo accounts you control. Look where they land.
- Run every sending domain through a free DNS checker for SPF, DKIM and DMARC.
- Check your bounce rate for the last 30 days against the 2% line.
- Count the out-of-office replies.
- Pull twenty contacts at random and read them. Right title, right company, right size?
If all five come back clean and replies are still thin, that is when the problem is interesting enough to pay for help, because it is probably the offer or the market rather than the plumbing. For checking the message itself, the free checker covers the copy half in your browser.
What to pay, and what to avoid
A fair one-off audit is $300 to $800. It should name the findings, rank them, and tell you the fix order — and it should be willing to end with "your infrastructure is fine, your offer is the problem," because sometimes that is the finding.
Be careful with free audits from agencies. Most check DNS records, declare something broken, and quote a retainer to fix it. The DNS check took them ninety seconds, and the thing they found is often not the thing causing your symptom.
The same applies in reverse: an audit that cannot show you real inbox placement, with screenshots, is reading dashboards you could read yourself.