7 Reasons Your Email Open Rates Are Tanking (And How To Save Them)

> "My open rate has progressively been destroyed over the last 5 months... from just under 50% to about 15%."

If your open rates are in freefall, you have a problem. And it's probably not your subject lines.

Here's what's actually happening — and how to fix it before you're completely blacklisted.

1. You're Sending To Dead Subscribers

The problem: Your list includes people who haven't opened in months (or years). Every email you send them that they don't open tells Gmail/Yahoo that your emails aren't valuable.

> "That inactive customer from 2018? Billable. That person who clicked 'no marketing' at checkout? Billable."

The fix:

- Create a segment: "Not opened in 90 days"

- Run a win-back campaign: 2-3 emails, final chance

- If they still don't engage, suppress them

Impact: Cleaning your list can improve open rates by 10-20% immediately.

2. Deliverability Death Spiral

The problem: Low engagement → emails go to spam → even lower engagement → worse deliverability → death spiral.

> "For a small sender on a shared platform like Klaviyo, you're probably having spam folder issues due to low engagement or shared domain issues."

How to check:

- Send a test email to Gmail, Yahoo, Outlook

- Check if it lands in Primary, Promotions, or Spam

- Use a tool like mail-tester.com

The fix:

- Stop sending to unengaged subscribers (see #1)

- Improve engagement with engaged segments first

- Consider dedicated sending domain if on shared IP

3. You're Sending Too Much (Or Too Little)

Too much: Subscribers get fatigued, stop opening, mark as spam.

Too little: Subscribers forget who you are, don't recognize your emails.

> "We send out an email 8-10 times a year — tops."

8-10 per year is too little. Subscribers forget you exist.

> "8 emails a year is definitely way too low. We would recommend a minimum of 8 emails a month for a list your size."

The sweet spot: Most ecommerce brands should send 8-12 campaigns per month, plus flows.

4. Your Sending Reputation Is Shot

The problem: If you've been flagged as a spammer (even accidentally), your emails won't reach inboxes.

How to check:

- Google Postmaster Tools (free)

- Check your domain reputation

- Look for spikes in spam complaints

Common causes:

- Purchased email lists (never do this)

- Sending to old, unverified lists

- High spam complaint rate

- Getting flagged by spam traps

The fix: If your reputation is damaged, you may need to:

- Create a new sending subdomain

- Warm up slowly with engaged subscribers only

- Gradually expand sending volume

5. Your Emails Look Like Spam

The problem: Spam filters look at your content, not just your sending history.

Spam triggers:

- ALL CAPS in subject lines

- Excessive exclamation points!!!

- Words like "FREE" "WINNER" "ACT NOW"

- Too many images, not enough text

- Broken links or suspicious URLs

The fix: Write like a human. Read your emails out loud. Would you open this?

6. Welcome Flow Isn't Warming New Subscribers

The problem: New subscribers join your list, receive nothing for 3 weeks, then suddenly get a promotional blast. They don't remember you → mark as spam.

> "I used to get like 74% open rate on my first Welcome Flow email (which people have to open to get a coupon code). Now it's like 24%."

The fix:

- Welcome email should go out immediately (within minutes)

- First few emails should be high value, low sell

- Build the relationship before aggressive promotion

Why welcome flow matters for deliverability: It trains subscribers to open your emails from day one.

7. You Migrated Poorly

The problem: Switching ESPs requires careful list warming. Migrating and blasting your full list immediately tanks deliverability.

> "3 months+ migration timeline & warm up routine... Absolute nightmare of an experience!"

If you've migrated recently:

- Start by sending only to most engaged subscribers

- Gradually expand over 4-8 weeks

- Monitor deliverability metrics closely

The Warning Signs

Early warning:

- Open rates declining over weeks/months

- Click rates dropping faster than opens

- Unsubscribes increasing

Red alert:

- Open rates under 15%

- Lots of emails to Gmail/Yahoo going to spam

- Spam complaints over 0.1%

Emergency:

- Open rates under 10%

- Being blocklisted by major ISPs

- Emails not delivering at all

What To Do Right Now

Immediate actions:

1. Stop sending to anyone who hasn't opened in 90 days

2. Test your deliverability (send to yourself at Gmail, Yahoo, Outlook)

3. Check spam complaints in your ESP

This week:

1. Clean your list (suppress non-engagers)

2. Fix any obvious spam triggers in your emails

3. Verify your sending domain/DKIM/SPF settings

Ongoing:

1. Segment aggressively — don't blast everyone

2. Monitor deliverability weekly

3. Keep list hygiene as a regular practice

Need Help Diagnosing?

> "I have multiple websites and have used Klaviyo for years. I was not seeing the ROI."

Sometimes you're too close to see the problem. Our Klaviyo Audit includes:

- Full deliverability check

- List health assessment

- Flow audit

- Revenue attribution analysis

We'll tell you exactly what's killing your open rates — and how to fix it.