Optimizing Email Deliverability

Optimizing Email Deliverability
Ed Forteau is an email marketing expert with more than 10 years of experience in email automation and deliverability. In this guide, he explains how email automation works from a technical perspective, what filtering and security measures are at play, and how to ensure that emails are consistently placed in recipient’s inboxes, including subscription emails, cold outreach emails, and transactional emails.

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Questions covered in this guide

Why does deliverability matter?

A third of your emails could be going to spam – when we do deliverability audits we find 20%, 30%, even 40% of the emails were going to spam. People are complacent about it, but they shouldn’t be.

Until you fix the problem, it’s hard to know what you’re missing – for example, I worked with a client who, it turned out, had 35% of his emails going to spam. He didn’t feel it because the problem had been going on for a long time. After we optimized, he hosted another event, and made $20,000 more than normal from improved uptake. The moral of the story is: if you have a deliverability problem, fix it. You don’t know how much money it’s costing you and it’s probably more than you think. 

What should your goals be around email deliverability?

Shoot for above industry average open and click rates to get into the inbox – everyone looks at their email average based on the industry average which is 20% open rate and 2% click-through rate. But if you’re only holding yourself to the industry average, you’re getting frowned upon by the mailbox providers (who view higher open and click rates as a sign that emails are wanted).
  • Target open rates of 30% or higher, with 8% open rates within the first hour of sending.
  • Target CTRs of at least 3%, ideally in the 5 – 15% range (or higher).

Privacy changes will limit your ability to see open rates, so shoot for higher click rates – the first one we’re going to see in fall 2021 is the Apple iOS 15 privacy change. This is going to eliminate our ability to see open rates for Apple users. So, we need to try to get click rates in the 10-15 percent range so that we have enough data that we can decide on what to do with those subscribers.

Make sure you’re getting into the inbox quickly – you don’t want there to be a delay in your email arriving. The goal should be to reach your recipient’s inbox in seconds. This is especially true for transactional emails (e.g. delivery of lead magnets, double-ops ins) because the expectation is that those emails will arrive instantly. People will refresh their inbox once or twice, but then give up if your email isn’t there. About half of email automation users have a timing problem.

Why is deliverability such a challenge?

Automation looks like spam – there are over 300 billion emails sent every day, and 85% of them are spam. Spammers are using automation to get their emails out, so when legitimate business email uses automation, it looks like it’s coming from a spammer. 

Mailbox providers are protecting subscribers – as far as the mail providers are concerned, email recipients are their customers, and they need to protect them from whatever spam is out there. So, a lot of legitimate email ends up going to spam or gets blocked. 

Spammers don’t authenticate their email addresses (you should) – one of the ways to overcome the “automation looks like spam” challenge is to authenticate your emails. If you’ve authenticated your email address, a spammer can’t hack into your account and send emails, which gives mailbox providers greater confidence that emails from you are legitimate. 

What are the categories of tech tools in the email space? What does each do?

Mailbox providers – where you house your email (e.g. Google, Outlook, Yahoo). Mailbox providers send out emails via shared IP addresses that they own. You could send out emails via your SMTP from your hosting account connected directly from your domain, but I don’t typically recommend that because Google and Outlook have higher-quality IPs.

Email Service Providers (ESPs) – list management systems and email automation tools (e.g. Hubspot, Marketo, Keap/Infusionsoft, ActiveCampaign, ConstantContact). These allow you to set up automation and segment your list to send the right message to the right person at the right time, based on how they behaved with your emails, and where they are in the buyer’s journey. 

Note: ESPs have IPs of varying quality – ESPs send mail via shared IP addresses, and any given ESP has different IPs of poor, medium, and high quality. They want to protect the reputation of their good IPs, so if you’re a sender with high engagement (open rates >30%, >8% open rates within the first hour after sending, click-through rates of 5-15%), you’re more likely to be put on a high-quality IP (you might still have to ask). If you generate average engagement (open rates around 20%, click-through rates around 2%), you’re likely going to be on a medium quality IP, with a portion of your emails going to promotion or spam.

Automated outreach tools – e.g. Lemlist, Reply.io, Quickmail), used for cold email, these send email from your mailbox. They tend to have simpler automation that just allows you to set up sequences and set some action after a recipient opens or clicks on an email.

Simple Mail Transfer Protocol (SMTP) – these are used most for transactional emails (e.g. SendGrid, Mailgun, Postmark–Postmark is the one I recommend). An SMTP is used by mail servers to send, receive, and/or relay outgoing mail between email senders and receivers (so ESPs and mailboxes also use SMTPs). You might layer in your own SMTP if you need to be sure you get a high-quality IP address.

What are the different types of emails businesses send, and what are the relevant differences when it comes to deliverability?

Marketing Emails – automated emails sent to a list of subscribers who’ve opted in to receiving mail from you.

Sent from: typically marketing emails are sent from your email service provider (ESP) via a shared IP address owned by the ESP. Or, you might layer in your own SMTP, in which case emails would come from the IP address your SMTP provides.

Be careful with:
  • Send no more than 3 emails to anyone who’s not opening – if your open rate drops below the 30% range, the mailbox providers start putting your emails into promotion folders, which make them harder to see, which pushes open rates even lower, which can lead you to get marked as spam.
  • Use automation to increase engagement – send one email out in which you’re providing some really good value (e.g. a lead magnet) to entice them to click so that you can determine their interest. If they click the email, then you use automation to send another email to them after they’ve had a chance to consume the video or special report (10-30 minutes later). When we do that, we’re getting an open rate on the first email somewhere between 30 to 60%, then click-through rates of 20%. For the follow-up email, we see open rates in the 80-90% range, and that helps overall domain authority.
  • As open rates go away, clicks are especially important – if new policies take open rates out of the equation, we have to do things that generate a high click-through rate (like providing high-quality lead magnets). That way you can use clicks to decide who stays on our list, and who we remove.

Outreach/Cold Email – automated prospecting emails, sent to people who have not opted in. Typically you have a sequence of emails organized into outreach campaigns.

Sent from: your mailbox provider (e.g. Gmail, Outlook) via a shared IP provided by the mailbox provider, much like regular one-on-one email.

Be careful with:
  • Don’t send more than 200 emails per day – unlike when you send mass marketing broadcasts via an ESP, mailbox providers will limit the number of emails you can send per day. Sending any more than 200 emails a day will put your Google Workspace or Outlook 365 accounts at risk. The stated limits for both services are around 250 emails per day, but they are assuming you are sending emails to colleagues and clients. If you consistently sent 250 emails, it would raise all kinds of red flags.
  • Don’t put too many emails in a sequence if they’re not engaging – cold email is usually approached with a sequence of 3-7+ emails; if somebody replies they get taken off your list, if they don’t, you send the next one. The idea with the long sequence is to follow up until you get a response, and you do get some people that way, but it can be at the detriment of your domain reputation, as engagement tends to fall off as the sequence progresses.
  • Don’t use your primary domain – set up a separate look-alike domain for cold email (e.g. yourname.co, yourname.net, or tryyourname.com). That way, if your domain reputation decreases (as is common with high volumes of cold email), it won’t impact your primary domain.
  • Switch from Gmail to Outlook – for whatever reason, Outlook has excellent deliverability, both to Outlook accounts and Google workspace or Gmail accounts. The only caveat: don’t buy your domain directly from Outlook (ironically, that can lead to an Outlook to Outlook deliverability problem). Buy the domain from a registrar like GoDaddy or Namecheap, and then set up the account through Outlook.

Transactional Emails – these include confirmations (e.g. of an opt-in, an order, or a delivery) log-in credentials, password resets, support tickets communication, proposals, and invoices. These tend to be emails that need to make it to the primary inbox in a timely way. 

Sent from: your ESP’s shared IP (if sent from a marketing automation system, like an opt-in confirmation) or your SMTP provider (if triggered within your app, like a password reset, or if you layer an SMTP over your ESP).

Be careful with:
  • Make sure it comes on time – it could be login credentials, or a special report, or the proposal you just promised on the phone–the expectation is that it’s going to arrive immediately. If it doesn’t get there immediately, the person’s not blaming your ESP or their mailbox provider, they’re blaming you. 
  • If transactional delivery is slow or bad, get a new IP – do a test and time it; if it takes more than a few seconds, you have a sender IP problem. You can ask your ESP to change your IPs, or add a secondary SMTP server that has high sender quality (I recommend Postmark, others like SendGrid are popular but have issues). 
Pro Tip:
  • Use the same domain for your transactional emails and marketing emails – transactional emails usually have very high open rates. If you use the same domain for transactional and marketing emails you get the benefit of the high open rate to boost your average open rates.

One-on-One Emails – general emails that write and send.

Sent from: your mailbox provider’s shared IP.

Be careful with:
  • Don’t use your primary domain for cold email or marketing email – use your primary domain for one-on-one email, and set up separate look-alikes for cold email and marketing email (e.g. yourname.co, yourname.net, or tryyourname.com). With domains used for cold email and marketing, there’s a good chance you’ll have an issue getting an email delivered at some point, and you don’t want that to happen when you’re sending a proposal.

In basic terms, how does automated email work? What “steps” does the email go through in its journey to the recipient?

Step 1: A sender writes an email – when sending out an email, you start by writing it in your mailbox or loading it into your ESP. Then you press send. 

Step 2: The email goes through the sending outbound server – the email goes to the SMTP, either the one you’re using or the SMTP of your ESP or mailbox provider.

Step 3: Clearinghouse – to look at both IP (from your ESP or SMTP) and your domain, to make sure neither is on a blocklist.

Step 3: Inbound mail server authentication – your recipient’s mail server, where they’re going to do another security check for SPF, DKIM, DMARC.

Step 4: Mailbox provider filtering – mail is sorted into the primary inbox, promotional inbox, spam, or is blocked.

What do mailbox providers check when deciding if an email is legitimate?

Security and authentication checks – to check if your domain is authenticated, and that you’re the legitimate sender of that email. There are three main checks:
  • SPF – Sender Policy Framework – this restricts who sends email from your domain.
  • DKIM – DomainKeys Identified Mail – this makes sure messages aren’t altered in transit between servers.
  • DMARC – Domain-based Message Authentication, Reporting, and Conformance. Think of this like a home security system; if there is a breach, alarms go off. There are three levels of DMARC. One is just having it in place, the second is to quarantine bad emails, and the third is to block emails from going out that aren’t authenticated. Outlook does a check and looks for DMARC to be set at the highest level.

Domain reputation – domain reputation is a sender score that rates the quality of your domain. If you’ve had many complaints against your domain, like spam complaints, or if somebody marks your email as spam, it impacts your domain reputation (but you might not know about it). We recommend that everyone set up a Google webmaster tool account that’ll monitor your domain reputations.

Sender IP reputation – you don’t have any control over the IP reputation, because it’s coming from your ESP or your mailbox provider. You can determine what your IP reputation is through a tool like GlockApps.

Content – content quality is measured by a combination of the words you use, and the links you include:
  • The words you use – “spammy” words, avoid being too sales-focused early on. Once you’ve developed a domain reputation over a long period, you can get pretty salesy in your emails and won’t be penalized for it. 
  • Links count and quality – don’t put too many links in your emails. If you want to get a high click rate and focus, just use one link in your email and make sure the link’s domain quality is good. 
  • The images you use – images most likely won’t put you in the spam folder, but they will probably put you in the promotional folder. 

If you have emails ending up in spam folders, what might be going wrong, and what can you do? 

The IP or domain could be on a blocklist – a blocklist is a real-time list that identifies IP addresses or domains that are known to send spam (Spamhaus is the biggest). If you get on their list (or your ESP’s IP is on the list) you’re going to run into deliverability issues.

The Sender IPs could be low quality – even if they’re not on a blacklist, low-quality sender IPs can land in spam or promotions. Request new Sender IPs from your ESP, or add an SMTP server with high-quality IPs

You could be using spammy words or bad links – we find that this doesn’t happen all that often in B2B, but when it does, links are more often the problem.

How can you build and protect your domain’s reputation?

Continuously monitor your reputation – for subscription email, sign up for Google Postmaster Tools or Senderscore.org.

Warm-up new domains – warming up your emails establishes your domain with the mailbox providers. You can send emails to trusted recipients yourself, but it’s usually easier to use a service that has a bunch of accounts that will engage with your emails. Ultimately you want to have people open and reply to your emails to show mailbox providers that your emails are welcomed by their users. Typically the warm-up process takes about two weeks. And then you can slowly begin to leave it on and then slowly start sending out your warm emails.

Don’t keep emailing non-responsive recipients – try to keep your follow-up sequence to 3 emails or less. Every time you send an email to someone who hasn’t opened your previous email, you will see a lower open rate. It’s common practice, but it will hurt your domain reputation and you will see more and more of your emails going to the promotional folder, spam, or blocked altogether.

What are the most important pieces to get right?

Make sure you set up (and check) your domain security keys – make sure your email account is properly authenticated and that you check them because they can always change and be updated.

Make sure you keep up with up it making sure you keep up with any updates from your ESP, mailbox provider, and other apps connected with your email account. That is probably the biggest area where marketers fall short. Pay attention to what the mailbox providers are requiring because their requirements are constantly changing. 

What are the common pitfalls?

With cold emails, don’t send more sequenced emails to non-openers – every time you send an email to someone who hasn’t opened your emails, you’re hurting your domain reputation. 

With subscription email, don’t leave disengaged people on your list – if a subscriber is inactive for 30 days, 60 days, or 90 days (depending upon how frequently they email them), you want to remove them before Gmail or Outlook does.

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