Email marketing audit: A step-by-step checklist to find what’s hurting your results

Campaigns go out, metrics look okay-ish, nothing improves. Sound familiar? Whether you’ve been sending for two months or two years, the cause is usually a handful of small issues across your list, deliverability, content, and automation, not one big problem. An email marketing audit finds them in one sitting. Pull your last few months of campaign data first, so you’re not hunting for numbers mid-audit.

What is an email marketing audit, and why bother?

An email marketing audit is a check-up for your entire email marketing setup. You go through your list, your numbers, and your automations to see what’s working and what’s dragging your results down.

Done right, it tells you exactly which fix will move your numbers the most, instead of you guessing where to spend your time next.

The email marketing audit checklist

This checklist covers the five areas that affect email performance most: list health, deliverability, performance metrics, content and design, and automation flows. Work through each area in order. Every section ends with a pass signal, a flag signal, and a clear next action if something is off.

1. List health

Your list quality affects every metric downstream. A list full of inactive or invalid addresses drags down your open and click rates, increases bounces, and signals to inbox providers that your emails aren’t worth delivering. So before you look at your metrics, check that the right people are on your list in the first place.

• How did your subscribers join? Opt-in form, imported contacts, or something else? Any purchased or scraped contacts need to be removed now; sending to people who didn’t ask to hear from you is the fastest way to damage your sender reputation.
• Is your list growing net-positive? Compare new subscribers against unsubscribes each month. A shrinking list isn’t automatically a crisis, but a consistent downward trend is worth investigating.
• What percentage hasn’t opened in 90+ days? Above 30% inactive is a deliverability risk, not just a content problem. Inbox providers use engagement signals to judge whether your emails belong in the inbox — a large pool of non-openers pulls those signals down for everyone on your list.
• Any hard bounce spikes recently? A sudden increase in hard bounces signals a bad signup source or stale data that’s been sitting on your list.
• Are all subscribers confirmed via double opt-in? Double opt-in filters out mistyped addresses and disengaged signups before they become list quality problems.
• Do you have consent records, and does your unsubscribe link actually work? Open one of your own recent email campaigns and click the unsubscribe link in the footer. Confirm it loads, processes the request without asking for a login or extra information, and actually removes you from future sends. Under GDPR, you also need a documented record of how each subscriber consented to join your list. Under CAN-SPAM, every commercial email needs a working opt-out, your sender identity has to be accurate, and opt-out requests need to be honored within 10 business days. 

SiteGround Email Marketing includes double opt-in and easy opt-out by default, covering the GDPR side, but CAN-SPAM compliance (accurate sender info, honoring opt-outs on time) is still on you to maintain. The audit is a good moment to confirm both are in place.

✅ Pass: list growing, under 20% inactive, hard bounces under 2%, all contacts opted in.
⚠️ Flag: list shrinking, over 30% inactive, recent bounce spike, non-opt-in contacts present.
→ If flagged: run a re-engagement campaign before your next send to give inactive subscribers one last chance to confirm interest. Remove hard bounces immediately. Never send to purchased or scraped lists.

2. Email deliverability

Email deliverability is the layer everything else sits on. If your emails don’t land in the inbox, nothing else in this audit matters. This section checks the technical signals inbox providers use to decide whether to trust your sends.

• Bounce rate per campaign. A hard bounce means the email address doesn’t exist or is permanently invalid. A soft bounce is a temporary issue: the mailbox is full, the server is down. Hard bounces need to be removed; soft bounces can be retried, but a pattern of soft bounces from the same address is worth investigating.
• Spam complaint rate. Above 0.1% is a live risk. Gmail’s bulk sender guidelines (updated in 2024) set 0.10% as the threshold at which deliverability starts to degrade, and 0.30% as the point where sending can be blocked outright.
• SPF, DKIM, and DMARC — are all three configured? SPF tells inbox providers your domain is authorized to send. DKIM adds a digital signature that proves the email really came from you and wasn’t altered along the way. DMARC tells inbox providers what to do if SPF or DKIM fail. If your DNS is managed through SiteGround, all three are set up automatically. If it’s hosted elsewhere, you might need to add SPF and DKIM manually and check that DMARC is in place too. Worth confirming either way if it’s been a while since setup.
• Any blocklist hits? A blocklist is a list of domains and IP addresses flagged as spam sources. If yours ends up on one, your emails may get rejected or sent to spam no matter how clean your list is. Check via MXToolbox or Google Postmaster Tools, both free. A hit doesn’t always mean something serious; it can happen after a single high-complaint send. To resolve it, pause sending for a few days, remove the contacts who triggered the complaints, and request delisting from the blocklist’s site once the issue is fixed.
• Suppression lists synced across all sending tools? If you use more than one platform to send email, unsubscribes and complaints need to be reflected everywhere. A subscriber who opted out via one tool and then receives a message through another is a complaint waiting to happen.

✅ Pass: bounce rate under 2%, spam complaints under 0.1%, SPF/DKIM/DMARC confirmed, no blocklist hits.
⚠️ Flag: bounce rate climbing, spam complaints above 0.1%, authentication gaps, blocklist hit.
→ If flagged: fix authentication first. See the full email deliverability guide for step-by-step setup instructions. Everything else in this audit depends on your emails actually reaching the inbox.

3. Performance metrics

Once you know your emails are being delivered, the next question is whether they’re working. Compare your last 10 campaigns against the email marketing benchmarks below. Look for trends across your sends, not one-off results. A single bad campaign doesn’t tell you much on its own.

Metric	Healthy range	Needs attention
Open rate	20–30%	Below 15%
Click-through rate	2–5%	Below 1%
Unsubscribe rate	Below 2% (1–2% is typical)	Above 2%
Bounce rate	Below 2%	Above 2%
Spam complaint rate	Below 0.1%	Above 0.1%

Benchmarks shift depending on your industry and list size. For example, B2B accounts usually see higher open rates, while ecommerce and high-volume senders tend to run lower. Worth knowing too: open rates are getting less reliable these days, since Apple’s Mail Privacy Protection and email security bots can inflate the numbers without anyone actually opening your email. Treat these benchmarks as a general guide, not a number you need to hit exactly.

Now, back to those patterns we mentioned: which subject lines pulled your highest open rates? Which CTAs or content types got the most clicks? Is there a send day or time that consistently does better than the rest? This is more useful than any benchmark, since it tells you what your specific audience actually responds to.

✅ Pass: most campaigns within benchmark ranges, stable or improving trend.
⚠️ Flag: open rate below 15%, CTR stuck below 1%, unsubscribe rate climbing.
→ If flagged: open rate issues usually point to subject lines or list quality. CTR issues usually point to content relevance or CTA clarity. Audit those areas next.

4. Content and design

Deliverability gets your email to the inbox, but content and design decide whether anyone actually opens it, reads it, or clicks anything once they do.

• Read your last five subject lines out loud. Would you open them? Subject lines that over-promise, underdeliver, or say nothing specific are the most common reason open rates stay flat. 
• Is your email preheader doing any work? Preview text is the line of copy that appears next to your subject line in most inboxes. If it’s auto-populated from the first line of your email body (“View this email in your browser”), you’re wasting the second line of inbox attention you have.
• Open one of your emails on a mobile screen. Is the call-to-action button tappable without zooming? Does the layout hold, or does it collapse into a wall of text? The majority of messages are now opened on mobile, so a broken email marketing design is a reliable way to lose clicks regardless of how good the content is.
• One clear call to action per email. Multiple competing CTAs dilute clicks. If you’re asking subscribers to visit your blog, reply to a question, and check out a product offer in the same email, they’ll often do none of them.
• Consistent brand voice across campaigns? If each email sounds like it was written by a different person, subscribers lose the sense of who they’re hearing from, which makes them less likely to open the next one.
• Are image alt texts filled in? This matters for accessibility and, in some inbox configurations, for whether your email renders legibly when images are blocked.
• Are you segmenting, or does everyone get the same email? A single welcome offer sent to brand-new leads and three-year customers alike is a missed opportunity, not a strategy. Even basic segmentation like new vs. existing customers usually lifts both open and click rates because the content is more relevant to whoever’s reading it. In SiteGround Email Marketing, you can segment contacts based on their campaign interactions directly from the platform.

✅ Pass: clean mobile render, single clear CTA, subject lines that accurately reflect content, consistent voice.
⚠️ Flag: broken mobile layout, multiple competing CTAs, subject lines that over-promise.
→ If flagged: start with mobile rendering and CTA consolidation: both have a direct impact on CTR.

5. Automation flows

Automated flows often get set up once and then forgotten. That’s fine for the first few months, but a welcome sequence with stale copy, a broken trigger, or an outdated offer is quietly working against you every time a new subscriber joins.

• List every active flow. In SiteGround Email Marketing, your flows live under Automations > Manage Automations — open it and write down every one that’s active. Welcome series, lead nurture, re-engagement, freebie delivery. Flows you can’t name are flows you haven’t checked.
• Test each one with a fresh email address. Does the flow actually trigger and send? Join the group that triggers it and confirm the emails arrive. A broken automation doesn’t send you an error notification — it just stops working.
• Check open and click rates per flow vs. your campaign average. In the Automations section of your dashboard, find the Completed column and click through to see per-flow stats. Below-average performance usually means broken logic, stale content, or a mismatch between the trigger group and the audience in it.
• When did you last review the copy inside each flow? If the answer is “when I set it up,” that’s the flag. Copy that made sense six months ago may no longer reflect your current offer, pricing, or tone.
• Are trigger conditions still accurate? Automations in SiteGround Email Marketing trigger when a contact joins a specific group. Check that the right subscribers are being added to the right groups — a contact landing in the wrong group gets the wrong sequence.
• Are flows suppressed correctly? A subscriber shouldn’t be in a welcome group and a re-engagement group at the same time. Overlapping flows send mixed signals and push complaint rates up.

✅ Pass: all flows tested and triggering, performing at or above campaign average, content reviewed in the last six months.
⚠️ Flag: untested flows, below-average performance, any flow not reviewed in six or more months, suppression gaps.
→ If flagged: test before anything else. A broken flow damages your sender reputation with every non-delivery. The welcome email guide is worth a read if your welcome sequence hasn’t been touched since launch.

What to fix first

Working through the checklist is one thing. Here’s what to actually do with what you found, and in what order.

Fix now: deliverability and authentication.

These sit underneath every other metric. A clean list with well-written emails still fails if your messages aren’t reaching the inbox. If you flagged anything in the deliverability section, start here today, before your next send.

Fix this week: list hygiene.
Remove hard bounces, suppress non-opt-in contacts, and launch a re-engagement campaign for inactive subscribers. 

A smaller, cleaner list consistently outperforms a large, stale one. Fewer engaged subscribers will generate better results than a bloated list full of people who stopped paying attention months ago.

Fix this month: content and flows.
Subject line testing, CTA consolidation, a fresh review of your welcome sequence copy. A/B test one variable at a time so you know what actually moved the needle.

Ongoing: set a 90-day reminder.
One audit won’t fix everything. The value compounds when you run it quarterly and compare results over time. If you’re fixing the same things every quarter without improvement, that’s usually a sign the issue is structural: an outdated platform, a list that’s never been properly segmented, or an email strategy that needs rebuilding rather than patching.

SiteGround Email Marketing gives you the campaign data, automation builder, and sending infrastructure to run this entire process from one place, no separate analytics tools, no patchwork of platforms.

Make your audit process a habit

An email marketing audit isn’t about chasing perfect numbers. It’s about knowing where your time pays off most, whether that’s a deliverability fix, a cleaner list, or a flow that’s underperformed for months. Work through the five areas, fix what’s flagged in order, and set a reminder to do it again in 90 days.

Ready to see your email campaign data in one place? SiteGround Email Marketing gives you the metrics, the tools, and the automation builder to put your findings to work.

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Frequently asked questions about email marketing audit