SaaS Email Metrics That Actually Matter (And What to Do When They’re Low)

Most B2B SaaS founders are tracking email metrics that don’t drive results. 

Here’s a breakdown of the email metrics that actually matter, how to diagnose what’s broken, and what to do to improve performance. Whether you're sending onboarding sequences, lifecycle campaigns, or demand-gen promos, this playbook shows you how to do it right.

Is Email Dead?

Before we dive into metrics, let’s address the elephant in the room. No, email is not dead. In fact, email marketing revenue is expected to reach $17.9 billion in 2027, a rise of over $10 billion since 2020.

It’s especially valuable in B2B, where 77% of B2B buyers say they prefer to be contacted by email rather than any other channel. So, ensuring that you’re tracking the correct metrics is key.

4 Email Metrics Worth Tracking

Let’s get this out of the way: Vanity metrics won’t help you. We’re here for KPIs that tie to business outcomes, such as revenue, engagement, and retention.

Here are the four that matter most:

1. Conversion Rate – Your conversion rate is the primary metric to focus on. Did someone book a demo, start a trial, or download content? If not, the rest doesn’t matter.
2. Click-Through Rate (CTR) – This metric shows if your content resonates and drives action.
3. Unsubscribe Rate – Spikes here usually mean message fatigue or poor segmentation.
4. Bounce Rate (soft vs. hard) – Reflects the health of your list and impacts deliverability.

Bonus metric for onboarding or nurturing: Time to conversion post-click. If you're looking to drive product adoption, this one is gold.

Open rates are still discussed and are helpful for testing subject lines, but they’re directional only. Especially after Apple’s Mail Privacy Protection update, they’re no longer a reliable metric.

Metrics by Email Type

Different email types require different success criteria. Here’s how I break it down:

• Lifecycle Emails – Lifecycle emails are used to engage existing leads or customers over time. They help nurture relationships, drive feature adoption, and support long-term retention. Prioritize CTR, feature adoption, and product usage.
• Promotional Emails – These are typically used to drive short-term actions, such as demo bookings or content downloads. CTR and conversions are key metrics for promotional emails, as they drive the pipeline and new revenue.
• Onboarding Emails – Sent to new users or customers, these guide recipients toward activation and success with your product. Onboarding emails focus on activation events and time to value. These are crucial for reducing churn and increasing trial-to-paid conversion rates.

Match the metric to the job of the email, and always link performance back to the outcome it supports. Don’t expect the same outcomes across the board.

What to Do When Your SaaS Email Performance Drops

Around 45% of all emails are sent to spam, so if your emails aren't hitting the mark, run through this checklist to find out why: 

1. Deliverability – Are you hitting inboxes or the spam folder? Check your email sending reputation.
2. Segmentation – Is your list clean? Are you sending the right message to the right person?
3. Subject Line & Preview Text – If people aren’t opening, this is likely why.
4. CTA Placement & Clarity – If people aren’t clicking, check your CTA. Is it buried? Too aggressive? Too vague?
5. Compare to Past Wins – Revisit campaigns that worked. Look at tone, timing, and offers.

Most problems come down to poor targeting or weak messaging. Rather than adjusting your email template, start by adjusting segmentation and positioning. If that doesn’t work, then analyze your copy and messaging.

How to Fix It: Optimization Tactics

These are the highest impact levers I’ve used:

• A/B Test Subject Lines – Fastest win for engagement.
• Prune Your List – Remove disengaged contacts to boost deliverability.
• Send Less, Not More – Fewer, more relevant emails drive better performance.
• Segment-Based Content Variations – Don’t blast everyone. Tailor content to lifecycle stage or behavior.

These tactics aren’t just good hygiene. They lead to real performance gains, from increased conversion rates to improved customer lifetime value.

One of the most consistent wins I’ve seen? Early, clear CTAs. Rather than leaving the CTA towards the end, put it near the top. Then, ideally, repeat the CTA once in the body as well.

Common Email Pitfalls (and a Surprise Win)

Don’t trust:

• High open rates with low CTRs,
• Low unsubscribe rates that mask disengagement,
• Pretty HTML emails that get flagged as promo and underperform in plain text.

Small, well-placed changes like this can drive outsized results. But results may vary, so it’s always worth testing what works for your audience. Try testing variations of CTA language across campaigns, especially ones that reduce pressure or sound more exploratory, to see what resonates best with your audience.

Underrated Move: Re-Engagement Sequences

When you see that your email subscribers are unsubscribing or not opening your emails, a re-engagement campaign with "choose what you want to hear about" options can work wonders. 

They clean your list, improve sender reputation, and give your subscribers more control, resulting in better outcomes.

Why Emails Matter for SaaS Growth (and How Kalungi Can Help)

Writing simple, relevant emails that respect your audience isn’t just good etiquette. It’s how you get results. When your messaging feels human and focused, it earns attention, builds trust, and drives measurable outcomes like higher conversions, lower churn, and stronger revenue performance.

Need help making email a real growth driver? Kalungi’s full-service B2B SaaS marketing team has helped over 100 companies build campaigns that convert. Get in touch with us to see how we can help.