In this email deliverability guide, we’ll break down some core principles and also the “hacks” we’ve used in sending millions of emails a month for us and our clients to improve your own email deliverability rates.
If you’re having trouble reaching the inbox and are tired of seeing your beautiful emails in the spam folder, this guide will hopefully help fix that.
What is email deliverability rate?
First off, to fix something, we should know what needs fixing.
If you’re struggling to get your emails out of spam or delivered at all, this mostly has to do with your email deliverability rate.
Your email deliverability rate is simply the rate at which emails reach the inbox.
So if emails get blocked by the ISP (like Gmail), or they bounce because of a mistyped email, then this decreases your email deliverability rate hurts your email reputation (your email “street cred”).
We want an excellent reputation with the email gods, so to fix this, let’s first determine your email deliverability rate.
How do you calculate your email deliverability rate?
You can calculate your email deliverability rate by dividing your total number of emails delivered by the total number of emails sent. Then multiply that number by 100 to get your percentage.
Email Deliverability Rate = (# of Emails Delivered / Total # of Emails Sent) x 100.
Pretty straight forward.
- (100 delivered / 1000 sent) x 100 = 10%. (Terrible delivery rate)
- (950 delivered / 1000 sent) x 100 = 95%. (Good delivery rate)
Note: Most platforms provide the number of emails delivered, but if you’re not sure, then subtract the email bounces from the total sent to get your delivered number (Total sent – bounced = delivered).
What is a good email delivery rate?
Ideally, you want to always be above a 95% email delivery rate at all times.
This keeps your reputation high and the email gods satisfied.
If your email deliverability rate dips below 95%, here are some things you can do to improve based on what we’ve done sending millions of emails monthly for ourselves and clients.
Protect your sending reputation
This is super important for getting your emails to reach the inbox.
Your email reputation goes up for every delivered email, and down for every bounce or spam report. The lower your reputation, the less likely you are to reach the inbox.
Note: Your reputation is not the same thing as email deliverability. Your reputation involves several factors, typically within a 30-day window of your email sending history.
If you’re using any of the common email platforms out there, they typically control this for you, so chances are you don’t know your email reputation. The problem is, you are sharing a reputation with other people.
You can also check your reputation score using the following tools:
Choose the right email service
You want to choose an email service that keeps their own IP addresses clean. This way, you’ll see a high delivery rate for your emails.
Most shared email platforms will stop bad senders from hurting everyone’s reputation by shutting down their accounts.
It’s why many platforms are strict on what they allow people to send. This can be a good thing, but it also limits how you control your own sending reputation.
If you’re planning to send high-volume emails, take more control of your own sending reputation.
At LeadEngines, we allow our email marketers to control their own reputation by connecting directly to your favorite email delivery service (or your own SMTP) and skipping the middle man platforms entirely.
We recommend using email delivery services like SendGrid to control your own reputation. You can track your own email reputation and connect to a platform like ours to handle the email sending itself.
If you prefer to stick with your email tool, no problem, just make sure they have an excellent reputation.
If you’re seeing your emails go to spam, then you may be on a blacklist.
Also known as Realtime blacklist, DNSBL or RBL. You typically end up on a blacklist when you email a spam trap email or are getting flagged for spam often.
If you’re not sure, then use MX Toolbox to check. It’s free, and checks over 100 blacklists.
Just enter your domain name or email IP address to see if you are on any blacklists.
For this article, we ran our domain leadengines.com through a blacklist check and, as you can see, we aren’t on any blacklists (and ideally stays that way!).
If you are listed, you can click the links provided by MX Tools to contact each blacklist site and get removed directly.
It can take some time to get off each, and we’ll write a more detailed article in the future on how to do this soon.
Authenticate your domain
Authenticating your domain for email sending is crucial for improved deliverability.
Most email services offer this feature, but check and make sure. Typically, you will need to authenticate your domain by updating your DNS records for your domain.
Depending on the email service you choose, they will provide your host values to add to your domain records. These will verify your email and authenticate your domain.
Don’t skip this, especially if you’re planning to send a high-volume of emails.
Check the SPF, DKIM, and DMARC for your domain
If you’re having issues with email deliverability, check your SPF, DKIM, and DMARC keys.
To check if your keys are good, I recommend using MX Toolbox again, specifically their super tool.
Just enter your domain and select SPF or DKIM from the options to check your domain for issues.
These basically authenticate emails so spammers can ‘t spoof them. Otherwise, anyone could email pretending to be a website they don’t own. So you need to update records from your email platform to prove you own the domain.
- SPF (sender policy framework) – Specifies which IP addresses and host names have permission to send email from the specific domain.
- DKIM (Domain Keys Identified Mail) – A digital signature that checks if an email was allowed by the owner of the domain.
- DMARC (Domain-based Message Authentication Reporting and Conformance) – Another authentication layer that works with SPF and DKIM to prevent email phishing.
You don’t need to get into the specifics of each (unless you’re handling it for your company or into that kind of stuff), but you should know how to at least check if everything is good.
Follow the recommendations on MX Tools to fix each of the issues in your domain.
Use a sub-domain for email sending
We also recommend using a sub domain for sending your emails. This will protect your main domain from being blacklisted.
Let’s say you have a team member who accidentally emails your list without an unsubscribe link. Oops.
While it might not seem like a big deal, if enough of those people can’t unsubscribe and report spam instead, you could get blacklisted. If your main domain gets blacklisted, now your regular company emails would end up in the spam folder as well.
This could hurt your entire business pretty quickly.
So we recommend using sub-domains like “news.yourcompany.com” to keep your main domain more protected.
Get a dedicated IP & warm it up
This is a bit more advanced, but highly recommended.
By getting a dedicated IP, you can take more control over your own reputation. Depending on the email delivery service you use, you can ask for a dedicated IP or upgrade your account.
At LeadEngines, we allow our customers to use almost any API or SMTP service they want, so these services easily allow you to add a dedicated IP in just a few clicks.
This allows you to get off shared IP addresses and build your own reputation without worrying about other companies ruining your deliverability.
We recommend a dedicated IP once you hit at least 25,000 in daily email sends. You can get it before, but it may be overkill.
If you get a dedicated IP address, you’ll want to warm it up first.
Send Grid has an amazing warmup guide available you can follow here.
Reduce your bounce rate
If you are seeing a high bounce rate, this could cause your email reputation to drop quickly. Thus affecting your email deliverability.
You want to keep your bounce rate below 2%. Anything higher and you’re risking your deliverability and reputation.
Bounced emails can happen from several things, including bad emails, dead emails, or mistyped emails that have joined your subscriber list.
There are specifically 2 types of email bounces:
- Hard bounce
- Soft bounce
A hard bounce occurs usually when an email no longer exists, never existed, or a server has blocked emails completely. These types of bounces are bad for reputation if you are sending to too many of them. Sometimes, a hard bounce can still occur even for a real email addresses because of firewall or spam filters.
Soft bounces occur more often and are less harmful to your reputation. These happen because of a full mailbox, mis-configured email, inactive email, and lots of other reasons.
You should handle dard bounces and soft bounces differently. Most email platforms, including ours, usually remove hard bounced emails for you automatically.
For soft bounces, you’ll want to remove them if they bounce often, typically 15 times or more.
You can also prevent hard bounces by cleaning your list regularly, which is our next suggestion.
Eliminate & clean high-risk emails
Before you hit send on that next email, you’ll want to scrub your email list for bad emails that could harm your email sending reputation and cause hard bounces.
Even if you didn’t buy a list and get real email opt-ins, you’re still at risk.
There are plenty of people who mistype their email on forms. People also deactivate or delete emails all the time, so old emails can be risky to send to for your reputation.
This can cause plenty of issues when you send emails to your list with bounced emails and high-risk emails.
We recommend using an email validation service such as Emailable to clean your list and remove risky emails. We love their tool, and they even give you 250 credits to try them out.
If you use LeadEngines, we also have a built in Emailable API integration so you can validate your emails.
Confirmed or double opt-ins
Using confirmed or double opt-ins can improve the quality of your list.
Since a new email sign up has to be confirmed, it reduces the chance of fake or mistyped emails entering your list.
It’s not perfect, but it helps.
Just keep in mind the tradeoffs. Even though you may think this is better, it’s not always true.
When using double or confirmed opt-ins, you are creating more friction to join your email list.
This helps improve quality, but you will lose many people who forget to confirm, and we’re really interested. Sometimes the welcome or confirmation email can get lost as well in their inbox and they won’t confirm.
Our preference is still single opt-in, and there is a lot of evidence that supports why single opt-in is still king. The team over at Litmus has done an amazing comparison of single opt-in vs double option.
Add a reminder of why they subscribed to the top of your email
If you want to increase deliverability, a simple strategy is to reduce your spam complaints by reminding people of why they subscribed.
We add this to the TOP of our email, not the bottom.
We add it to the top of the email so they can click unsubscribe first, before hitting the spam button at the top of their email.
We’d rather people unsubscribe than hit spam, because this hurts your reputation.
If you’re worried about getting too many unsubscribes, you’re thinking short term. It’s better to have that person unsubscribe, then to report you as spam.
Add the unsubscribe header to your email
Another tactic to improve your deliverability and reduce spam complaints is to add an unsubscribe header to your emails. This is a short piece of code that will add an easy unsubscribe link to your emails in inboxes like Gmail.
They look like this:
To implement this code, use the template below:
List-Unsubscribe: <mailto: email@example.com?subject=unsubscribe>, <http://www.yourcompany.com/unsubscribe.html>
When your email is sent, it should look something like this:
From: Your Company <firstname.lastname@example.org> To: John Doe <email@example.com> Subject: <subject line> Date: Thu, 03 Feb 2022 09:01:00 -0600 List-Unsubscribe: <mailto: firstname.lastname@example.org?subject=unsubscribe>, <http://www.yourcompany.com/unsubscribe.html>
Using this in your email templates will help you by allowing subscribers to unsubscribe from your list quickly before hitting the spam button.
At LeadEngines, we include this by default for our customers, but check with your email service to see if this can be added.
Avoid words that trigger spam in your emails
Another tactic to improve deliverability is to avoid words that trigger spam in your emails. There is no definitive list, but here are some words to avoid:
- Money – Anything related to money like cash, dollars, get paid, etc. Use these sparingly or not at all as they could trigger spam filters.
- Free – Using the word free a few times may not be bad, but using it a lot in one email can trigger spam filters. Be careful using words like 100% off, gifts, rebates, etc.
- Sex – This one might seem obvious, but using any words related to sex can easily get you in the spam folder. We all hate those emails for a reason and it’s why they usually end up in spam. Just avoid the word all together if you can.
- Drugs/Pills – Another obvious one, but avoid using drugs or pill related words in your emails. While it might seem like a fun idea to compare your product to a drug, it could hurt your deliverability if triggered by spam filters.
There are plenty of lists out there about words not to use, but we suggest just being smart about your sending. If you wouldn’t open it, don’t expect your subscribers to either.
Avoid heavy use of emojis
Using emojis in your emails might seem like a great idea, and it’s becoming even more popular, but this could start triggering spam filters.
Especially as we see more people overusing them to get attention.
Definitely don’t use emojis related to money, sex, or drugs/pills as these also trigger spam filters (Sorry that eggplant emoji just isn’t a good idea for your emails).
Avoid spam traps
Spam traps can quickly hurt your email sending reputation and deliverability.
So how do you avoid them?
Clean your list and do it regularly.
There are 2 main spam traps to watch out for:
- Pristine email addresses
- Recycled email addresses
Pristine emails are new emails added to your email list by bots. If you send to these, it signals you have bad email collection practices or bought a list from someone.
Recycled emails are old emails that are recycled for spam trap purposes. If you send to these emails, it signals you are not cleaning up your list often enough.
Check your email content
Improving your email content can also improve deliverability. Not just the text content but the email code itself.
We recommend running your emails through a mail testing app such as Unspam.email. It’s easy and free to use.
You simply send a test email to the test address it provides and it will provide suggestions for you along with a score.
Overall, when generating your emails, make sure you have clean HTML code that is mobile friendly and looks good in all browsers.
You can also use this free email markup testing tool from Google Postmaster to check your email markup and make sure it’s properly optimized.
At LeadEngines, our email builder automatically creates mobile friendly and inbox friendly emails that are optimized. If you’re using another email platform, then make sure they also generate optimized emails for you.
A simple strategy to improve email deliverability is to just email your list consistently.
This is heavily underrated, yet very effective.
If you email your list at the same time and days, this creates a habit for your readers to open and read your emails. Which signals to the ISP’s that your emails are not spam.
This is especially important if you are on a dedicated IP. Most email IPs can grow stale over 30 days and may need to be warmed up again if not being used.
If you’re on a shared IP, this is not so much an issue, but it’s still important to email consistently or else subscribers may forget they signed up to hear from you and start reporting you as spam.
We recommend emailing at minimum at least once per week. If you offer a monthly newsletter, that’s ok too, but you may see less engagement since people will forget why they joined in the first place if they get emails only every 30 days.
Segment openers and clickers
This is also an underrated strategy to improve your deliverability, but we use it often.
It’s smart to segment your list into the following segments:
- If emailing 2x per day – Anyone who has not engaged with your last 60 messages. (30 days)
- If emailing 1x per day – Anyone not engaged last 60 messages (60 days)
If you have low open rates for too long a week, you could end up in the spam folders.
That’s why you want to be sending to your most engaged users often.
Unsubscribe or reconfirm inactive users
Related to segmenting, you should also keep your email list tidy by removing inactive users often.
If someone hasn’t opened your emails in over 60 days, we recommend emailing reconfirming them or unsubscribing them completely.
The easiest way to do this is by segmenting users who haven’t opened in 60 days, and sending them the following email:
Subject: Is this the end? Ignore this email if you no longer want to hear from us.
We noticed you haven’t opened our emails in some time. Since you haven’t been reading our emails lately, we’ll take you off our list, and spare you the trouble of saying goodbye.
If you’ve just been busy, and prefer to stay on, click the button below and we’ll keep sending emails your way.
[Yes, please keep me on the list]
You can re-word that how you want, but make sure you add a button with a link for them to re-confirm their subscription or simply link out to a page on your website. This will add them to a “clickers” list, thus re-engaging them.
Improve email engagement
There are several engagement signals that can improve your email deliverability.
Here are the top ones we recommend you focus on:
- Open rate – This signals that your emails are being read. You want to be above 20% open rate minimum. Unfortunately, this may not be as effective anymore after the iOS 15 update that will trigger email opens even if they aren’t being read. Improve your open rates with better subject lines and sending to emails that are deliverable.
- Click rate – Even before the iOS updates, clicks were always king. It signals that emails are being opened and actually clicked. Improve your click rates by writing engaging content and improving your call to actions.
- Email forwarding – This signals to ISPs that your emails are worth reading. Like when mom forwards that important email over, this shows your emails are trustworthy and improves your reputation with the ISP.
- Favorite or Marked as Important – If an email is marked as favorite or important, this can also improve your reputation. ISPs like Gmail also see this as a positive indicator that your emails are trustworthy.
- Replies – This is a powerful engagement strategy and signals your emails are trustworthy. It’s a strategy we use as well, and it’s so powerful we created an entire section on it below.
Ask for email replies in your welcome email
Getting people to reply to your emails is a powerful inboxing strategy.
We use this strategy often to improve our deliverability and trust with the ISPs. When someone replies to your emails, this tells Gmail and the other email gods that people want to reply to your emails.
A powerful strategy we use is to ask people to reply to your email in the first welcome email.
Here’s an example from a Codie Sanchez over at Contrarian Thinking:
As you can see, she asks for a reply to her first welcome email.
A good strategy for this is to offer a gift also if they hit reply like copywriter Stefan Georgi does:
Notice he says to reply “Done” to the email and he’ll send you a free bonus.
Both Codie and Stefan understand the importance of email replies and it shows.
Do it and thank us later. 🙂
Ask subscribers to add you to the primary tab
Another strategy to improve deliverability is to ask subscribers to add you to the primary tab in Gmail. This also signals to Gmail specifically that the email is important. It also makes sure they receive it in their primary tab.
A good example of this is from the folks over at Morning Brew:
Even though not all subscribers will bother doing it, a few will and it will help improve your deliverability.
If you scrolled to the bottom and prefer the summary, here is a simple plan for improving your delivery:
Better deliverability =
High opens (20% +)
High clicks (2% +)
Low spam complaints (< 2%)
Low bounce rate (< 2%)
It’s not an official formula, but it works. We’ve seen it across sending millions of emails. If you can increase your opens and clicks, while decreasing your spam complaints and bounce rates, you should have a much higher inbox deliverability.
We hope this was helpful. If you have questions or feedback, leave a comment or hit us up on Twitter!