This is Week 2 of my rebuild-in-public series. Last week I wrote about de-indexing 1,300 pages from my website to try and save my SEO. That was a deliberate decision. I chose to do that.

This week’s disaster? I didn’t choose this one. This one chose me.

I reopened my newsletter after a period of not sending regularly. Within days of getting back into it, my open rate crashed to 11%. People started messaging me saying they hadn’t received my email. Others told me it landed in spam. One person, who’s been subscribed for years, said she’d completely stopped getting anything from me.

My first thought was that I’d broken something. My second thought was that ConvertKit had broken something. My third thought, after several hours of research at midnight with too much coffee and not enough patience, was a bit more nuanced than that.

It turns out that the entire email industry changed how it sends emails. And nobody sent me a memo. Well, technically they did. It probably went to spam.

What Actually Changed (And Why It Wasn’t My Fault)

Here’s what happened. In February 2024, Google and Yahoo introduced new rules for anyone sending bulk email. The short version: if you send a lot of email, you now have to prove you are who you say you are. No more riding on your email platform’s reputation. You need your own authentication set up on your own domain.

These weren’t suggestions. They were requirements. If you didn’t comply, your emails would start getting delayed, filtered to spam, or rejected outright. Google began enforcing gradually from February 2024, started rejecting non-compliant emails from April 2024, and by November 2025, tightened things further with permanent rejections for emails that don’t pass authentication.

Then Microsoft joined the party. From May 2025, Outlook, Hotmail, and Live.com started enforcing the same requirements. Non-compliant emails? Rejected.

So every major inbox provider in the world now requires proper email authentication. Every single one.

In response, email marketing platforms started pushing their users to set up something called a verified sending domain. ConvertKit did it. Mailchimp did it. ActiveCampaign did it. Klaviyo did it. They had to. The rules changed and they needed their users to comply.

I use ConvertKit (now called Kit), but this is not a ConvertKit problem. This is an email industry problem. If you’re on any platform, this applies to you.

What a Verified Sending Domain Actually Means (In Human English)

Right, let me explain this in a way that doesn’t require a computer science degree. Because when I first started looking into this, I felt like I’d wandered into a conversation that was absolutely not meant for me.

Imagine you’re sending a letter. Previously, your email platform was like a really reputable courier company. Gmail saw the courier’s uniform and thought, ‘Oh, I know these guys, they’re legit, let the letter through.’ It didn’t matter much who actually wrote the letter. The courier had a good reputation, so your letter got delivered.

A verified sending domain changes that. Now, instead of Gmail checking the courier’s ID badge, it checks yours. Gmail is now looking at your domain directly and asking, ‘Do I trust this person?’

And if you’ve just set this up? Gmail’s answer is basically ‘I have no idea who you are.’

It doesn’t matter that you’ve been emailing from that domain for ten years. It doesn’t matter that your subscribers love your content. The infrastructure changed, and Gmail is re-evaluating you from scratch. You’re the new kid at school, except you’re 40 and you’ve been going to that school for a decade.

That’s what happened to me. I set up the verified sending domain because the industry required it. And my open rate went from healthy to 11% almost immediately.

This Is Not Just Me

After my open rate tanked, I did what any reasonable person does: I panicked slightly, drank more coffee, and then started researching obsessively.

I went through forums, Facebook groups, Reddit threads, and support communities. And I found the same story everywhere. People on ConvertKit reporting drops. People on Mailchimp reporting drops. ActiveCampaign users confused about why DKIM suddenly tanked their deliverability. Klaviyo users seeing open rates halve overnight after migrating or setting up domain authentication.

ActiveCampaign even published a help article explaining exactly this issue. They said that before February 2024, they allowed customers to rely on their mail servers for DKIM signing, which gave customers access to their servers’ good reputation. Now that senders are required to sign DKIM themselves, the same list with some inactive subscribers suddenly looks like a spam operation to Gmail.

So this is industry-wide. This is structural. And it’s affecting people who have been sending email for years without any problems.

My first instinct was to switch platforms. Maybe ConvertKit was the problem. Maybe a different tool would fix it. I researched alternatives and came very close to moving.

But then I realised something important, the reputation follows your domain, not your platform. If I moved to Mailchimp tomorrow, Gmail would still be judging lilachbullock.com. I’d still need to warm up. I’d still need to rebuild trust. And I’d lose time migrating, rebuilding automations, and potentially introducing new issues.

Switching platforms when your domain reputation is damaged is like getting a new phone number because your Wi-Fi is down. Different problem entirely.

So I stayed. And I got to work.

Why This Matters (Beyond Vanity Metrics)

OK so why did I spend an entire week losing sleep over a percentage? Because it’s not just a percentage.  Email is a core revenue channel for my business. It drives course sales, it drives affiliate revenue, it drives partnerships. When my emails don’t land in inboxes, people don’t see my content. When people don’t see my content, they don’t click. When they don’t click, the commercial side of the newsletter stops working.

An 11% open rate doesn’t just look bad on a dashboard. It means 89% of the people who signed up to hear from me aren’t hearing from me. That’s not a metrics problem. That’s a business problem.

And this is true for anyone who relies on email, whether you sell products, services, courses, or you’re building an audience for future monetisation. If your emails aren’t reaching inboxes, nothing downstream works.

The Technical Setup: What Actually Needs to Be in Place

Now this is the bit where it gets a little technical. I’ll do my best to keep it human. If you find your eyes glazing over, just keep going. The important part is that each of these is like a lock on your front door. Miss one, and Gmail thinks you left the door wide open for burglars.

There are four main records you need configured in your DNS. DNS stands for Domain Name System, and it’s basically the phonebook of the internet. It tells everyone where to find things associated with your domain, including who is allowed to send email on your behalf.

Here’s what I set up:

SPF (Sender Policy Framework)

Think of SPF as a guest list for a party. It tells Gmail ‘These are the servers that are allowed to send email from my domain. If it’s not on this list, it’s not from me.’

I updated my SPF record to include my email platform’s mail servers. Without this, Gmail sees your email and thinks ‘I don’t know who sent this, could be anyone, could be a scammer in a basement.’

DKIM (DomainKeys Identified Mail)

DKIM is like a wax seal on a letter. It’s a cryptographic signature that your email platform stamps on every email. When Gmail receives it, it checks the seal against your DNS records. If the seal matches, Gmail knows the email hasn’t been tampered with and really came from your domain.

I added two DKIM records. If that sounds like a lot, it’s not. It’s two lines of text in your DNS settings. It took about three minutes to add them. It took about three hours to figure out that I needed to add them.

DMARC (Domain-based Message Authentication, Reporting and Conformance)

DMARC is the bouncer. It tells Gmail what to do if an email fails the SPF or DKIM checks. Should Gmail reject it? Quarantine it? Let it through but make a note?

I set mine to p=none, which basically means don’t reject anything yet, just monitor and report back. This is the recommended starting point. You want to see what’s happening before you start telling Gmail to reject things. Imagine installing CCTV before you hire a security guard.

Return-Path

This one is less glamorous but still important. The return-path tells Gmail where to send bounce notifications. If someone’s email address doesn’t exist anymore and your email bounces, the return-path makes sure that bounce report comes back through your domain rather than through some generic address. It helps everything look consistent and aligned, which is what Gmail wants to see.

I also set up Google Postmaster Tools. This is a free dashboard from Google that shows you how Gmail rates your domain. It tracks things like compliance scores, spam complaint rates, and whether your authentication is passing or failing.

Here’s the important bit though, Postmaster Tools is like a thermometer. It tells you your temperature. It does not cure your fever. It’s monitoring only. Useful, but not a fix.

You can set it up at postmaster.google.com. It takes about five minutes and it’s one of those things you’ll wish you’d done sooner.

What Really Caused My Open Rate to Crash

So, with all the technical stuff now in place, here’s what I think went wrong. And I say  think because deliverability isn’t an exact science. It’s more of weather forecasting, you can see the data, you can identify patterns, but sometimes Gmail just decides it doesn’t like you today.

First, my initial email went out before the DKIM records had fully propagated. I sent my first broadcast on January 25th, but the DKIM records weren’t validated until January 27th. That means my very first email after the change likely had authentication issues. Not a great first impression. Imagine showing up to a job interview with your shirt on inside out. That was my email on January 25th.

Second, the reputation reset kicked in. As I explained above, Gmail was now evaluating my domain directly instead of trusting the platform’s shared reputation. And as far as Gmail was concerned, I was a stranger.

Third, I sent to my full list too quickly. I should have started with my most engaged subscribers and gradually expanded. Instead, I included people who hadn’t opened an email in months. Gmail saw a big send with low engagement and thought ah, spam.  Which is annoying, because it wasn’t spam. It was my actual newsletter that people had signed up for. But Gmail doesn’t care about your feelings.

Fourth, my domain email mailbox was nearly full at 78% capacity. If it had hit 100%, emails would have started bouncing. And bounces during a reputation rebuild are absolutely devastating. It’s as if you’re trying to rebuild your credit score while simultaneously missing payments.

Each of these individually would have been manageable. Together, they created a perfect storm that pushed my open rate to 11%.

What I Did to Fix It (Step by Step)

Here’s exactly what I did, in order. If you’re going through something similar, you can follow these steps.

Step 1: Audited All DNS Records

I ran a complete check on my SPF, DKIM, DMARC, and return-path records. I verified that each one was correctly configured, pointing to the right servers, and had fully propagated through the DNS system. This is the foundation. If any of these are wrong, nothing else you do will matter. It’s the same as trying to fix the plumbing while the water mains are off.

Step 2: Set Up Google Postmaster Tools

I verified my domain in Postmaster Tools so I could track how Gmail was rating my authentication, spam complaints, and overall compliance. Without this, you’re guessing. With it, you’re at least guessing with data.

Step 3: Segmented My Audience

This was the most important operational step. I stopped sending to my full list. I created a segment of engaged subscribers only, people who had opened or clicked an email in the last 90 days. This smaller group would naturally have higher open rates, which sends positive signals back to Gmail. It’s like when you’re at a party and you start a conversation with people who want to talk to you, rather than shouting across the room at everyone.

Step 4: Excluded Cold Subscribers

I temporarily removed anyone who hadn’t engaged in months from my sends. I didn’t delete them. I just parked them. The goal was to avoid sending to people who weren’t opening, because every unopened email drags your reputation down further.

Step 5: Changed My Email Style

I shifted from broadcast-style newsletters to a more personal, conversational tone. Shorter emails. Direct questions. The kind of email you’d reply to.

This matters because Gmail uses engagement signals to decide where your email lands. Opens are one signal. But replies are a much stronger signal. When someone replies to your email, Gmail interprets that as a real relationship. Not marketing. Not spam. An actual human conversation.

So I started asking specific questions at the end of each email. Not vague stuff like let me know your thoughts but questions that people could answer in one sentence. The reply rate went up. And I believe this was a significant factor in the recovery.

Step 6: Sent Smaller, More Frequent Batches

Instead of one big blast to everyone, I sent smaller batches more consistently. This gives Gmail a steady drip of positive signals rather than one massive spike that looks suspicious. Think of it like watering a plant. A little bit every day works. Dumping a bucket on it once a week drowns it.

Step 7: Cleared the Mailbox

I cleaned out my domain email inbox to make sure it wasn’t going to fill up and start bouncing emails. Simple but easy to overlook.

Step 8: Monitored and Adjusted

I checked Postmaster Tools regularly. I tracked open rates by segment. I watched for spam complaints. And I adjusted my sending based on what the data showed. This isn’t a set-and-forget thing. It’s ongoing.

Results So Far (Honest)

My engaged segment is now at a 46% open rate. That’s a big recovery from 11%. I’m super pleased with that.

But the full list is not there yet. The segments that include less-engaged subscribers are still showing weaker numbers. The reputation rebuild is still in progress.

The general guidance from ConvertKit, from Google’s own documentation, and from everything I’ve researched, is that this process takes 2 to 4 weeks from the point where your DNS records are fully correct and you’re sending consistently to engaged subscribers. I’m still within that window.

So this is a progress report, not a victory lap. The trend is moving in the right direction. But I’m not done. And I’m not pretending to be.

What I’d Do Differently Next Time

If I had to go through this again (and I sincerely hope I don’t), here’s what I’d change:

• Segment before making any changes. Have your engaged segment ready to go so your very first send goes to people who will open it.
• Set up Google Postmaster Tools before your first broadcast. You want monitoring in place before things go wrong, not after.
• Check DKIM propagation before sending. I sent my first email before the records were fully live. Two days early. That was an expensive two days.
• Warm up slowly. Start with your 50 most engaged people. Then 100. Then 500. Give Gmail time to build trust. Don’t go from zero to full blast in one send.
• Clean your cold subscribers before the switch, not during the crisis. If I’d excluded inactive contacts from the start, the initial numbers would have been much healthier.
• Clear your domain mailbox. A nearly full inbox causing bounces during a reputation rebuild would have been catastrophic.
• Expect the dip and don’t panic. I know that sounds odd in a technical post, but watching your numbers crash when you’ve just restarted something is incredibly stressful. Knowing it’s temporary helps. Having a plan helps more.

The Bigger Lesson

Look, I used to think deliverability was a subject line problem. Write something catchy, send it at the right time, job done. It’s not. It’s so much deeper than that and I learned that the hard way this week (Though if you’re using the poop emoji in your subject line, we should talk.)

It’s infrastructure. It’s authentication records, domain reputation, engagement signals, and inbox provider algorithms. Most people never think about any of this until something breaks. And then it feels overwhelming because you’re trying to learn DNS configuration while watching your open rate sink.

I’ve been doing email marketing for over two decades. I have a large email list. And this still blindsided me. Not because I did something wrong, but because the rules changed underneath everyone and the transition isn’t smooth.

Google, Yahoo, and now Microsoft have all decided that email senders need to prove their identity. That’s probably a good thing for the long term. It means less spam, less phishing, and better inbox experiences for everyone. But the short-term cost is that legitimate senders like you and me get caught in the crossfire while our domain reputations rebuild.

The lesson from this week, same as last week with the de-indexing, is infrastructure before promotion. Don’t launch things, don’t push campaigns, don’t chase growth until the plumbing works. Because if the plumbing is broken, nothing else matters.

Who Should Care About This

This post is for you if:

• You use any email marketing platform and recently set up domain authentication
• Your open rates dropped suddenly and you can’t figure out why
• You’re thinking about switching email platforms to fix a deliverability problem
• You rely on email for any part of your revenue
• You’ve been sending for years and assume your reputation is fine
• You’re about to make DNS changes to your domain
• You had no idea any of this was happening (welcome to the club)

Deliverability isn’t something that just works automatically. It’s a system. And right now, that system is going through the biggest change in years.

What I’m Tracking Now

This is an ongoing experiment. Here’s what I’m monitoring:

• Gmail domain reputation in Postmaster Tools
• Authentication pass rates for SPF, DKIM, and DMARC
• Spam complaint rate
• Open rates by segment
• Click rates by segment
• Reply rate
• Inbox placement trends over time

I’ll keep reporting on these numbers as the series continues. If the reputation rebuilds fully, I’ll show you the data. If something else breaks, I’ll show you that too.

What Happens Next

This is Week 2 of the rebuild. Last week was structural SEO cleanup. This week was email infrastructure.

The pattern is the same, find the broken system, understand the root cause, fix it methodically, and track the results.

Next week I’ll be covering the next piece of the rebuild. Same approach. Real numbers. Real problems. Real frustration. No BS.

If you’re going through something similar, let me know. I read every reply. (And honestly, your replies are helping my Gmail reputation, so you’d be doing me a favour.)