When was the last time you checked if your emails actually reached the inbox? You don’t remember? That’s already a sign that something might be off.
You can write carefully crafted messages, but if they end up in the spam folder, they might as well not exist. This is the reason why so many email marketers discuss email deliverability audits.
They uncover what’s working, what’s broken, and where you’re losing trust with mailbox providers.
Mailbox providers give you data through tools and reports, and with the right audit, you can track real signals that shape your inbox placement. Sender reputation, bounce rates, and spam complaints all tell a story – you just need to listen.
The only question is: are you paying attention?
What is an email deliverability audit?
An email deliverability audit is a full review of your email program’s performance. It examines popular metrics like open rates and clicks, but the focus is on the hidden factors that determine whether your email message reaches the recipient’s inbox or lands in the spam folder.
The primary objective of this audit is to understand how email providers perceive your sending behavior. You learn whether your technical setup is solid, whether your sender reputation is healthy, and if there are risks, such as spam traps or invalid email addresses, hiding in your lists.
The audit is typically performed by deliverability specialists, email service providers, or consultants who understand how mailbox providers evaluate your sending reputation. Some businesses run audits with in-house teams if they have the right expertise, but most rely on deliverability tools and external consulting services.
How long does such an audit take?
A basic audit can be done in a few hours with the help of email deliverability tools. However, a deeper review, covering authentication protocols, IP reputation, and spam trap monitoring, can take a few days. The time span depends on the size of your email program and the number of campaigns under review.
When the audit is complete, you walk away with a clear picture of your deliverability issues and a plan to improve inbox placement.
Why does a deliverability audit matter?
You may wonder why this topic gets so much attention right now. There are many reasons, and we will start with the most crucial one:
Because it can help you with inbox placement
Inbox placement is fragile. Every email you send is judged in milliseconds by mailbox providers. They look at your sending reputation, your technical setup, and even how recipients interact with your messages.
A deliverability audit sheds light on these silent judgments and allows you to adjust accordingly.
Because with it, you can handle deliverability challenges better
Mailbox providers and internet service providers have raised the bar. Previously, just publishing authentication protocols was enough to pass technical checks. Now, mailbox providers combine them with your sending behavior (patterns, volumes, reputation signals).
Audits are therefore essential, since they don’t just confirm whether authentication exists. They check how consistently and correctly you’re applying it.
Because it can show you warning signs for customer engagement
Another reason audits matter is the link between sender reputation and customer engagement. Positive engagement signals (like opens, replies, or clicks) help your email program look trustworthy. On the other hand, poor engagement suggests that your messages may be unwanted.
Without regular audits, you miss the warning signs that your campaigns are sliding toward poor inbox placement.
Because it can measure spam complaints
A high spam complaint rate tells providers that your emails annoy recipients. But a small number of complaints can already trigger filters and damage your email delivery across different providers.
An audit measures those complaints, compares them with bounce rates, and shows potential complaints before they get worse.
Signs you need a deliverability audit
So how do you know it’s time to take a closer look at your email program?
- The first red flag is a sudden drop in inbox placement rate. You might notice open rates falling even when subject lines stay strong. This is often a signal that more emails land in the spam folder instead of the primary inbox.
- Bounce rates creeping up is another warning sign. Hard bounces often point to invalid email addresses or outdated lists. Soft bounces may result from temporary issues, but a steady rise suggests a more significant problem with your sender reputation.
- Pay attention when marketing emails or transactional emails start slipping into spam. Transactional emails (like password resets or order confirmations) are usually seen as safe. If even those land in spam, it’s a clear sign of deliverability issues. It means mailbox providers no longer trust your email program’s performance.
- Your IP reputation or domain reputation sinking is another common trigger. Both are monitored by mailbox providers. If your IP address has a history of sending spam complaints, every new campaign is judged more harshly. A poor domain reputation is just as damaging, especially when tied to cold email campaigns or high-volume sends.
- Engagement metrics can tell the same story. Poor engagement (fewer opens, clicks, and replies) suggests that your audience no longer interacts with your emails. Mailbox providers treat that as a negative signal.
Plus, there can be many subtle signs.
You might notice delayed delivery, inconsistent inbox placement across providers, or more potential spam complaints flagged in internal reports. These are subtle hints that delivery challenges are already accumulating.
A deliverability audit can connect the dots and show the full scope.
What a deliverability audit reveals
An email deliverability audit isn’t always identical. It can highlight different results depending on the approach. Plus, the depth of the audit decides how much detail you see.
Nevertheless, it shows details that are usually hidden in daily email work. It’s the stuff you don’t see in your regular campaign dashboard.
Here are examples of what areas an email deliverability audit analyzes and what they include:
Technical issues
- DNS records, authentication protocols, and digital signatures must all align.
- They need to be configured correctly, or mailbox providers start to doubt you.
- Even a small mistake here can quietly drag down inbox placement and make emails land in spam.
Reputation scores
- Sender score, IP reputation, and domain reputation are all measured.
- These scores are the trust signals that email providers use to decide if you’re reliable.
- Low numbers usually mean too many spam complaints or invalid addresses linked to your sending.
Content flags
- Subject lines and body copy are scanned for patterns that trigger spam filters.
- Overloaded promotional keywords, poor formatting, or suspicious links raise red flags.
- Even transactional emails can get blocked if the technical setup behind them is weak.
Spam traps and risky addresses
- These addresses look real but exist to catch careless senders.
- Once you hit them, your sender score sinks fast.
- An audit surfaces them so you can clean your list and avoid repeat hits.
The audit usually ends with a clear deliverability report.
With this report, sales teams and email marketers can see many actionable insights, for example, bounce rates compared to benchmarks, how often subject lines trigger spam filters, and where complaints come from.
Key steps of an email deliverability audit
Alright – we already know what an email deliverability audit is, why it matters, what it reveals, and what signs tell you that you need an audit.
Now it’s time to focus on the specific steps of a sample email deliverability audit.
Step 1: Check authentication protocols (SPF, DKIM, DMARC)
Start with the basics. Review your domain settings to confirm that you have SPF, DKIM, and DMARC enabled.
- SPF (Sender Policy Framework) tells providers which servers can send email for your domain.
- DKIM (DomainKeys Identified Mail) adds a digital signature that shows your emails haven’t been altered.
- DMARC (Domain-based Message Authentication, Reporting, and Conformance) ties everything together and tells providers what to do if SPF or DKIM checks fail.
If you’re unsure how to set these up, log in to your DNS records or contact your email service provider for assistance. Without this trio, you’ll trigger spam filters.
Step 2: Review sending reputation (IP address, domain, sender score)
Next, you need to determine how trustworthy your sending appears from the outside.
- Check your IP address to see if it’s ever been linked with sending spam. If you use a shared IP, remember that other people’s bad habits can drag you down too. Thus, ask your provider if you can move to a dedicated IP address once your volume is high enough.
- Look at your domain reputation as well. This shows whether your email domain has a clean history or if it’s been flagged for risky sending.
- And don’t forget your sender score. If the number is low, your emails are more likely to get blocked or filtered out.
Step 3: Inspect bounce rates and invalid email addresses
Look at your bounce rates. A few soft bounces here and there are normal, but if you see a rise, it’s a warning.
Also, go through your list and remove any invalid email addresses. Use an email verifier before running big campaigns. Keeping your list clean shows providers that you respect inboxes and helps your bounce rates stay low.
Step 4: Analyze inbox placement across email providers with deliverability tests
Run tests to see where your emails land. Of course, don’t just check Gmail. Send test campaigns to Yahoo, Outlook, and other mailbox providers, too.
Check if your messages reach the primary inbox, the promotions tab, or the spam folder. If you notice poor deliverability with one provider, dig into their specific rules. Each provider has its own spam filters, and you’ll need to adapt slightly for each one.
Step 5: Monitor spam complaint rate
Check how often people are hitting “mark as spam.” Most email service providers show you this number in their dashboards. If your spam complaint rate is climbing, review those campaigns.
Were the subject lines too pushy? Did you send too many emails at once? Adjust your email program so it respects recipients’ expectations. Next, try to keep complaints low, or mailbox providers will keep punishing your sender reputation.
Step 6: Use tools for extra visibility
Don’t audit in the dark – use tools that can really support your job. You can, for example, set up Google Postmaster Tools for your domain. It gives you data on reputation, spam rates, and email authentication results directly from Gmail.
Or go further and use tools like Woodpecker, which can support your deliverability strategy by combining monitoring, verification, and sending safeguards in one place.
Step 7: Audit your email campaign’s content to avoid spam filters
Finally, look at your content. Open up your most recent campaigns and check the basics:
- Do your subject lines sound like clickbait?
- Are you using too many images without enough plain text?
- Do your links match your email domain, or do they look suspicious?
Tweak your content so it feels clear, balanced, and trustworthy. A deliverability audit can even make sure your email message doesn’t trigger spam filters for silly reasons.
Common deliverability issues & pitfalls
Let’s be honest. Most deliverability problems don’t come out of nowhere. They’re usually caused by habits that sneak in over time.
One of the biggest pitfalls is poor list hygiene.
Sending to invalid addresses makes your bounce rates climb. Worse, you might hit spam traps. And once you land there, your sender reputation takes a hit. Regular list cleaning is the cure, but too many teams forget about it until performance drops.
Cold emails are another tricky area.
When you start sending from a new domain or IP address without warming it up, mailbox providers get suspicious. They see a sudden spike in activity and assume it’s spam. That’s because pushing high volumes too quickly doesn’t look natural. Even if your content is relevant, the numbers can work against you.
However, a slow warm-up process keeps your new sending identity safe. Providers prefer steady, consistent sending patterns over sudden bursts.
Another pitfall is ignoring deliverability challenges until it’s too late.
Many marketers focus on subject lines or campaign design, while inbox placement gets less attention. By the time bounce rates rise or inbox placement rates drop, recovery is harder. What you need is a proactive approach, as it can keep small issues from turning into major problems.
And yes, deliverability audits highlight these weak points before they spiral.
When and how often to audit your email program
Now you may wonder how often you really need to check your email program’s health.
It’s good to do an email deliverability audit when you:
- Start sending from a new domain or a new IP address. Mailbox providers don’t know you yet, so they watch your every move. An audit helps confirm that SPF, DKIM, and DMARC are set up and that your new sending identity looks safe. If you’re using a dedicated IP address, this step matters even more because its reputation depends only on you.
- Plan to increase volume or launch bigger cold email campaigns. This way, you spot deliverability issues early instead of discovering them after sending thousands of messages.
- Notice problems. If inbox placement starts dropping or marketing emails land in spam, don’t wait. Auditing at this point shows whether the cause is bounce rates, spam complaints, or domain reputation.
Besides that, make audits a habit.
A quarterly review works well for most businesses. At the very least, check twice a year. After all, regular audits keep your email program healthy and prevent small issues from turning into bigger deliverability challenges.
How Woodpecker supports deliverability success
Let us now introduce you to Woodpecker – a cold email tool that proves managing email deliverability doesn’t have to be complicated.
With Woodpecker, many of the key tasks that protect your deliverability are built right into the platform. That means even small teams without dedicated email specialists can keep their cold email campaigns running safely.
One of the biggest helpers in Woodpecker is free catch-all email verification, which can help you at the very start by checking your list for invalid email addresses – before you send a campaign. You can expect lower bounce rates and protect your domain from looking careless.
But there is also an automatic warm-up. Yes, Woodpecker takes care of the warm-up process. It sends gradual, realistic-looking emails that improve your email reputation over time. In this way, your emails get a real chance to land in inboxes.
Woodpecker also includes a Deliverability Monitor. It tracks key signals like sender score, spam complaints, and inbox placement trends. If it notices a risk, you get notified before it turns into a bigger deliverability issue.
For busy sales teams, it sounds like salvation: they save time and still keep campaigns from hitting sudden roadblocks.
Another safeguard is Adaptive Sending. It automatically adjusts your daily limits and sending intervals. It also mimics natural human behavior to protect your sending reputation.
The interesting part is that Woodpecker checks your domain audit, too. It verifies that SPF, DKIM, and DMARC are configured correctly.
The platform also offers a spam words and links checker. So before you hit send, it scans your email content for triggers that might set off spam filters.
And let’s not forget, that teams who manage multiple inboxes can also take advantage of Woodpecker, which includes inbox rotation. Instead of pushing hundreds of cold emails through one address, you can spread them across several inboxes. Your sending patterns are safe, and you reduce the risk of poor deliverability.
Also, for agencies or larger teams, there’s an automated audit for client domains.
Now you know why maintaining deliverability isn’t hard or impossible for Woodpecker. It’s totally manageable. What makes all this work is the combination. Verification, warm-up, adaptive sending, monitoring, and domain checks all play together to protect your inbox placement.
The result is simple: your carefully prepared cold emails reach the inbox, your campaigns avoid common deliverability pitfalls, and your sender reputation stays strong over time.
Improve your cold email campaigns with an email deliverability audit
Email deliverability audit steps are puzzle pieces. Put them together, and you’ll see a clear picture of how your emails perform and what’s stopping them from reaching the inbox.
The strength of an audit lies in visibility:
→ Without it, you are working in vain.
→ With it, you can view sender reputation, bounce rates, inbox placement rate, and spam complaints side by side.
You discover the patterns that explain why Gmail treats you differently from Outlook, or why engagement on transactional emails looks weaker than expected.
Think of your own situation. Have you checked whether your domain has authentication protocols configured correctly? Do you know how many invalid email addresses sit in your current list? Have you run any deliverability tests in the last six months? These questions define the difference between guessing and knowing.
That’s where Woodpecker comes in.
The platform takes the ongoing care of deliverability and makes it simpler. You can warm up new inboxes without technical work, verify emails in bulk before sending, rotate inboxes for safer volumes, and monitor deliverability in real time.
Deliverability audits show the weaknesses, while tools like Woodpecker give you the capacity to act quickly.
So, before launching your next campaign, ask yourself: Am I certain my emails land where they should? If not, run that audit, connect the dots, and take action with Woodpecker at your side.