r/emaildeliverability

I've been doing a lot of cold email cleanup recently and spent the last few weeks comparing different email verification platforms before uploading lists into campaigns.
One funny thing I noticed is that almost every marketer I talked to falls into one of these 3 "bounce camps"😂

1. The "Zero Bounce" people
2. These are usually agencies or high-volume senders.
3. Their main focus = keeping sender reputation safe
4. at scale.
5. The "Never Bounce" people
6. Mostly businesses that want a clean/simple Ul and don't want to overthink technical stuff.
7. The "Invalid Bounce" people
8. Usually smaller teams, indie hackers, or people testing cold email without wanting to spend a fortune first.
9. A lot of them care more about flexible pricing + decent accuracy instead of enterprise-style dashboards.

I spend a lot of time looking at what ESPs companies use. Got tired of digging through the email source every time, so I built a free Chrome extension that does it automatically.

It sits inside Gmail and shows you which platform sent each email. Mailchimp, Brevo, HubSpot, Klaviyo, whatever. It detects 140+ ESPs and also shows SPF/DKIM/DMARC authentication status. It also shows if HTML builders like Stripo and Beefree have been used.

In addition, it can also check BIMI and whether a VMC exists. You'll also see the sender IP and whether it's a shared or dedicated IP setup.

https://preview.redd.it/dqfuy488o22h1.png?width=1512&format=png&auto=webp&s=a22dfe5e40237eaca6a875ce681a86d7fe28b278

It works by scanning the email source for ESP fingerprints (tracking domains, header patterns, sending infrastructure). No personal data leaves your browser.

Deliverability folks have been the most enthusiastic users so far, which is why I'm posting here. Please let me know if there's any information you would like to see in addition.

The extension is called Email Detective and it's free on the Chrome Web Store.

We run a content site and also do cold email from the same domain. Traffic is up from AI content but I am worried it could hurt sender reputation. Has anyone seen ai seo services affect email deliverability? Should we split domains? I do not want our publishing scale to tank our outbound. Looking for real experience managing both channels safely.

Hey everyone, just wanted to share a quick pattern I’ve been noticing lately.

​A lot of people spend days rewrite-testing their email scripts or changing their offers because their replies drop to zero. But more often than not, the copy isn't the problem at all.

​If you are setting up your campaigns on default shared hosting networks, Google and Microsoft are likely just aggregating your domain with the bad sending habits of your server neighbors. The corporate mail gateways will quietly route your emails away from the primary inbox based purely on that network footprint, even if your text is perfect.

​Before you rewrite your whole script for the fifth time, it's usually worth double-checking that your backend infrastructure is actually isolated from the noise. Saves a lot of headaches.

I feel like a lot of deliverability problems come from the same few issues over and over again: poor list hygiene, weak authentication, sending too fast on a new domain, or ignoring engagement signals.

For people who’ve been through this, what’s the most common mistake you keep seeing?
And which fix actually moved the needle the most for you?

I’m especially curious about:

• SPF / DKIM / DMARC setup.
• Warm-up and ramp strategy.
• How often you clean inactive contacts.
• Whether you suppress non-engagers aggressively.

Would be great to hear real-world examples rather than the usual textbook advice.

Recently I spent some time recently looking at performance across different types of senders, from enterprise-level brands to small boutique setups.

We always warn high-volume senders about the risks of blasting and the need for strict throttling. But looking at the actual numbers, it’s the smaller senders who are getting absolutely hammered by the spam filters. I’ve been tracking patterns across thousands of accounts, and the gap is unreal.

low-volume senders are seeing average spam rates as high as 56%,

high-volume "power senders" are sitting much lower, around 18%

Essentially, the more you send, the better your inboxing seems to be.

It feels like we spend all our time talking about the danger of high volume, yet we’re ignoring a massive inconsistency crisis where small businesses and low-frequency senders are basically being treated as guilty until proven innocent by Gmail and Outlook.

My question is,

Do you think the filters are biased toward high-volume senders simply because they provide more data points for the algorithms to analyze?

How are you advising low-volume clients to stay out of the spam folder when they don't have the reputation weight of a major brand?

Any insights from your experience would be great. It can be from your brand or of your clients. Anything. Thanks.

I'm a web designer. Generic cold emails get 2-5% reply rates. But when I spend 30 mins personalizing each pitch (actually researching their site, their reviews, their pain points), reply rate jumps to 40%.

Problem: I can't scale 30 mins per prospect. That's 25 hours for 50 emails.

Question for solopreneurs: How do you handle cold outreach at scale without burning out? Do you automate parts of it, or just accept the time investment?

Curious what actually works for people.

We run an ecommerce email program and occasionally have flash sales where we need to send 3-4x our normal daily volume in a single blast. Every time we do this our deliverability tanks for days after. Anyone found a good way to handle volume spikes without wrecking your sender reputation?

We tried warming up the volume gradually the day before by sending a smaller campaign first. Helped a little but not enough. We also cleaned the list before every flash sale so were only hitting engaged contacts. Made the numbers look better on paper but the deliverability dip still happened.

Our ESP doesnt give us any control over sending speed per provider. It just blasts everything out as fast as it can. Starting to wonder if thats the actual problem but not sure what I can even do about it from my end.

We've been running our own sending infrastructure for a few years now. If I could go back and tell first-year me one thing it would be: get your SPF setup right on day one. Everything else you can fix later. This one gets exponentially harder.

Most ESPs start by having customers add CIDR ranges directly into their SPF records. Works fine at 10-20 customers. Then you scale and things start breaking in two ways.

The security gap

Your IP ranges grow, you add broader CIDR blocks. If a spammer has an IP in that same range, they can pass SPF checks on your customers domain. Not great.

The operational nightmare (this is the real killer)

SPF has a hard limit of 10 DNS lookups. Sounds like plenty. Its not.

Take a customer on xyz.com sending through Google Workspace, HubSpot, and your ESP. Thats three SPF includes. But:

→ spf.google.com alone resolves to spf1, spf2, spf3.google.com, each pointing to different CIDR ranges. Thats 4 lookups from one entry.

HubSpot adds more. By the time they add your record theyre at 9 or 10 lookups

Now you need to change your infra. Swap IPs, restructure CIDR ranges, whatever.

Every customer has to update their DNS. And if your change breaks their SPF record youre not just breaking email from your ESP. Youre breaking their Google Workspace. Their HubSpot campaigns. Everything. And they wont know why until their CEOs emails start bouncing.

Multiply that by hundreds of customers each with different DNS setups. Its months of coordination for what should be a routine infra change.

What we ended up doing was return path CNAME mapping. Customers point a CNAME to us, we manage SPF behind it. We can swap our entire infrastructure without a single customer touching their DNS.

Not a novel approach, plenty of mature senders do this. But the number of ESPs ive talked to who started with direct SPF and are now stuck is wild.