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Better Done Than Perfect · Season 6 · Episode 1

Email Deliverability with Lauren Meyer

You'll learn about the mechanism of how an email is delivered, the factors that affect deliverability, why you should use engagement metrics as proxies for deliverability, and more.

Lauren Meyer

Can we, mere mortals of email marketing, influence email deliverability? In this episode, we talk to Lauren Meyer, chief marketing officer at SocketLabs. You'll learn about the mechanism of how an email is delivered, the factors that affect deliverability, why you should use engagement metrics as proxies for deliverability, and more.

Show Notes 📝

Thanks for listening! If you found the episode useful, please spread the word on Twitter mentioning @userlist, or leave us a review on iTunes.

Key Learnings 💡

With over two decades in the email industry, Lauren has experienced different aspects of working with email: as a marketer, helping people with deliverability issues, and working with email service providers (ESPs).

"Most of my time was spent in the trenches of deliverability, compliance, anti-abuse, and just trying to make sure that customers were able to hit the inbox. There were also certain cases where we helped prevent spammers, phishers, and other nefarious actors from getting on our platform and sending bad emails."

Her vast experience with deliverability and compliance has helped her with her current position at SocketLabs:

"Our mission is ultimately to not just help direct senders excel at email and hit the inbox, but also help email service providers. So if you're a marketing automation platform, a CDP, or a healthcare CRM and you need to get emails over to your customer's customers, we make that really easy."

While it might seem like everything is simple after you hit that 'Send' button, it's more complicated behind the scenes. There's a lot of activity happening between hitting the 'Send' button and the message ending up, a lot of things can go wrong — and this is where SocketLabs comes in:

"If you've got a problem, we help you understand what that problem is, how to solve it, and then get you back and running without you having to completely wreck your day or spend a ton of time fixing your email problems."

How an email is delivered

To illustrate this process, think of sending emails like a phone conversation.

"So you start by entering somebody's phone number: there's a dial, there's a ringtone and then you see if it connects to an actual phone number. From there, hopefully somebody picks up the phone — so that's a good step. Once they do, they say: 'Hello,' and then you say: 'Hi, is (name) there?' Then they might say yes or no, or they say: 'That person doesn't live here. I don't know who you're talking about.'

So there are all these steps back and forth before you eventually get yourself into the inbox. There's a ton of data that's being passed back and forth."

And on that way into the inbox, there are also checks being performed for authentication:

"Looking at authentication protocols is like, 'okay, you say that you're Userlist. Are you actually Userlist or are you somebody else who's pretending to be from Userlist? Okay, cool. We think we've got enough confidence to let your mail into our system.'"

From there, the email has to run through different spam filters and get checked for other things to make sure your mail isn't malicious:

"They're still checking the authentication. They're checking your IP reputation, domain reputation, the reputation of links within your email and past user reaction to mail that you've sent."

And even if your email passes all these checks, there's still a possibility that it could end up in the spam folder or blackholed:

"They're finally delivering that either to the inbox because they think you deserve it or they're like, 'we think your mail is legitimate but we still don't think the person you're sending to actually wants that mail. So we're going to send it to the spam folder instead.'

Or there's this third option where sometimes your mail gets blackholed. In those cases, they've let you into their system because they thought initially that your mail looked pretty legit and then something between the transient period where they're trying to decide what to do with it, they decide, 'No, your mail is actually not as good as we thought it was. We're not going to deliver that to our user because that feels risky to them.'"

All these processes are performed by a machine with algorithms:

"It's really just a matter of you trying to show as many positive signals to mailbox providers as possible to say, 'I am legit. This user wants it and they probably signed up for it.' Try to reduce as many negative signals as possible and do as many things right as you can."

But for people who are running their own mail servers, the complexity of email deliverability can make it very challenging for them.

"You need to understand the inner workings of what that destination requires in order to get in. Think of it almost like going to a restaurant. Some restaurants require a nice dress code and you've got to wear a blazer or something like that. If you're a man, other places don't even care if you have a shirt on. You need to comply with the standards of the destinations that you're sending to."

And the challenges these small email providers face are due to a lot of factors:

"They're just not seeing enough volume to be able to understand the traffic that's happening and then react to it appropriately. Maybe they don't have the knowledge to do that. Maybe they just don't have the resources: they know there's a problem, but it's super low on the priority list because they only send to a couple addresses of that destination versus others. There's just a lot of things going on that you have to be really excellent at, making it difficult for those folks that are doing it on their own."

Delivery rate vs email deliverability

Delivery rate

Delivery rate is the ability to get messages into the mailbox provider's servers:

"The cool part about that is they actually give you feedback right at the end of that attempt to send. They will give you a response, either a favorable one that says, 'the mail's been accepted ' or they'll give you a negative response that says, 'we've rejected that mail and here's a little bit of a code that tells you why.'"


On the other hand, deliverability is all the steps following the mail being accepted into the provider's servers:

"They don't give you any feedback to tell you if the message went to the inbox, to the spam folder or if it got dropped. It's just sort of up to your interpretation."

Because there's so much involved with deliverability, email service providers and monitoring tools can help users make sense of it with the signals that they have access to:

"So we're looking at your engagement data like your opens, clicks, unsubscribes, and complaints, and trying to get a picture of what the user's doing. We're looking at the delivery rate to see if the mail was even received into those servers. We're looking at third party signals as well."

Tools can give you an idea of your ability to hit the inbox, but it's still an educated guess because it lacks the mailbox provider's feedback:

"So we're trying to factor in all of these different things to say: 'Your future ability to hit the inbox is around a 96 out of 100,' which is pretty good, right? But it's not really based on reality because there's no feedback coming from the mailbox providers. It's really just a very educated guess on behalf of the email service provider."

When making these educated guesses, email service providers are not the same:

"There are some that are fantastic: they pay attention to the data and they're constantly optimizing. Others that have been stood up and forgotten, and not paying attention to what's happening within the data."

Factors affecting deliverability


"Think of authentication kind of like your driver's license or passport. It's the thing that lets mailbox providers and recipients know that the mail is actually coming from the real you. As opposed to somebody pretending to be you to fool your users into giving away information or do something nefarious like downloading malware."

Email authentication involves three protocols (DMARC, DKIM, and SPF) and Lauren advises to ask your ESP about them because there are nuances to the way these should be set up for your different records.

The mechanics for authentication would involve several steps:

  1. Going to your domain hosting service
  2. Adding records on your hosting service
  3. Making sure that is confirmed in your email client

Showing up on recipients' inboxes unannounced

"Think of this as if somebody shows up to your front door and just starts knocking. You're like, 'Who is this person? What are they doing here?' You're gonna be a little bit wary. The inbox is not as intimate as your front door, but people really respect their inbox and want you to respect it as well.

So if they don't know who you are and if they've never heard from you, even if they're aware of who your brand is and know they haven't signed up, those things will really incite anger in people, which is going to lead to spam complaints."

Spam complaints will damage deliverability because it is a direct signal from the user that they don't want this email. And because ESPs can't determine if they opted in or not, they look at the signals of how the recipient acts to the email.

This is why Lauren stresses the importance of getting explicit permission from the recipients before sending them an email.

But what do you do when you want to send cold outreach emails?

"I don't recommend cold email as you're sending unsolicited messages to people. But if you're going to do it, make sure that it is highly targeted, relevant, and that it truly provides value."

If you do manage to get people to sign up through cold emails, it's best to set their expectations about what they are going to get and when:

"Is it newsletter content? Is it coupons? Is it something completely different? They want to understand what to expect from you."

Domain reputation and the factors that affect it

Domain reputation has become more important over the past few years. Unlike before, when it was just all about IP, there are now other factors involved:

"It's not just the domain, it's also the IP, and every other aspect. Even just the sender address also has an impact on your deliverability."

For example, even when you're sending from the same domain, like receipts@userlist.com and marketing@userlist.com, ESPs can separate them and see the difference in traffic shaping, volume, and user reaction behind each of them.

The links in your email can also affect your domain reputation:

"If you're pushing people to your website, cool, that's one type of domain. Also factor in all of the little social media links that you're using. Just literally every piece of content that's within the body of your email."

Over time, the recipient addresses can also affect the domain reputation:

"For example, if you send to a certain recipient and they never engage with your email. If GMail can see that that same recipient engages with other emails hitting their inbox, they're going to say, 'Okay, wow. This recipient is very engaged with email. They love email. They just don't love emails from you.'

Over time, that will start to impact your inbox placement with that specific recipient. And then there's a critical mass point where, if they see that same behavior with enough recipients, they start to push your mail to the spam folder at a greater rate."

Recovering domain reputation

If your domain reputation has been ruined for some reason, Lauren says that recovering it would depend on several factors.

For example, if you have a solid reputation but accidentally made a one-off mistake, ESPs will forgive you for that:

"You send to a list you shouldn't have, resulting in high spam complaints. You have a huge bounce rate because you sent an email to your suppression list. If something bad happens but it's a one-off, you're gonna get forgiveness for that."

But forgiveness also depends on how bad the mistake was:

"Mailbox providers are very forgiving if you've just made some small mistake and they can actually see the long tail history of your sending activity. This is really helpful because if they can see that you've been doing right by email all this time, then they're going to overlook that one time.

You can reach out to them and say, 'Hey, my mistake. Can you unblock us? That'd be great.' There are remediation steps that you can take.

But if you've been doing a lot of things wrong for quite a lot of time and it's just business as usual for you — you keep hitting send, you keep hitting spam traps, you keep having high bounce rates, you keep getting high spam complaints — it will continue getting worse and you're just poking the bear if you keep sending."

That's why you have to make sure to fix these problems immediately to save your domain reputation. If you're think moving on to a new domain to fix the problem, it won't solve anything. Those issues will follow you to that new domain:

"Just fix whatever is broken. Fix the reason why spam traps are ending up on your list. Fix the reason why you're having high spam complaint rates and then go beg for forgiveness from the mailbox provider that you're having a problem with."

Engagement metrics as a proxy for deliverability

Unlike bigger brands like GMail and Yahoo, not all ESPs can have access to all the data to help increase deliverability. That's why it's best to use engagement metrics as a proxy for deliverability.

You can look at positive signals like:

  • Open rates
  • Clicks
  • Conversions
  • Website traffic

"Even if you don't see a direct connection between the email engagement and deliverability, you can still look at positive signals. For example, you can see that there's a lift on your website. It's a positive indication that not only are you hitting the inbox, but also that recipients are engaging with that mail."

It's also important to look at the negative signals like spam complaints and unsubscribes:

"Those are signals from your recipient that they don't like something about what you're sending. It could be that they're not expecting to hear from you. It could be that they don't like the mail or they find it irrelevant. Maybe you send way too frequently and that's a problem because they wish you would send weekly instead of daily or five times a day."

Open rate

While open rates have been pretty inaccurate for quite some time, there's still value in looking at them on a destination level because it helps you gauge your inbox placement:

"When we're talking about deliverability and you're seeing a really low open rate, it's really important to look at the destination level open rates because this is where the magic happens.

Imagine if you see that your overall open rate is 30%. But when you look at it further, GMail is 30%, Yahoo is 28%, but Hotmail is at 10%. That's a very clear indication that you have some sort of inbox placement issue with Hotmail. If you're targeting all those different recipients, all those different destinations the same, you should expect pretty similar results."

But beyond the inbox placement, open rates are not a great engagement metric:

"You really don't know if that's a human that's opening the mail or if it's a machine checking to see if that's a legitimate email that's being sent. So you're not really sure what's happening there."

Clicks and conversions

So when it comes to engagement, it's better to focus on the clicks:

"While bots do sometimes click on the links, typically, it's a human-focused event."

And if you put the open rate, clicks, and conversions together, you'll get a good idea of your deliverability:

"For example, we want to look for people that are opening our emails. That's a sign that could tell you if it's an active address. We also see that they're clicking. But even if they're not opening or clicking, if you see that they're converting, making purchases on your website, or logging into their user account, that's a sign that they're still engaging with your brand. And so then they'll be okay with you sending them emails from time to time."

Looking at these three engagement metrics will also help you clean your email list:

"When you're sending emails to people for years with no sign of life from their side, that's when it's really going to start impacting your deliverability. And you're also just sending a lot of mail, more than you need to, which gets expensive over time."

Even without having full access to all the data, you can still try and connect the dots yourself with the available ones:

"Even if you're just doing a one off investigation from some small sample of your data, pull in the conversion data from your website and other tools that you're using, and kind of compare that. Try to put the full picture together to make your case: is your email program being effective or not?"

Final advice

Do be thoughtful.

"Be creative about how you're going to encourage your email recipients to engage with your emails and with your brand — both of which are good for your deliverability. It's also really good for building brand loyalty."

Don't use growth hacks to increase your inbox placements.

"Don't try to take a shortcut to growing your list to a very large one. Focus on quality over quantity. Don't purchase email lists. Don't send more emails in place of quality emails that are actually going to resonate with the recipients that you're sending to. Don't shoot first and ask for forgiveness later."

Thanks for listening! If you found the episode useful, please spread the word on Twitter mentioning @userlist, or leave us a review on iTunes.

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