Show me a publisher who is not reliant on email, and I’ll show you a publisher who probably doesn’t do much advertising volume, because anybody operating at scale uses email for everything from marketing, to audience development, to production reminders, to getting invoices out. As important as it is to every publisher, you’d think we’d all be good at it. We’re not.

As an email service provider, we are the first person called when clients think their invoices, production notices or marketing emails don’t get through to their clients. But, like most email providers, the problem is rarely with the deliverer of the email. There is an email ecosystem that all email senders live in, and it’s important to understand how to manage that ecosystem. Doing so will ensure vital functions in your business can be executed.

In this blog, I am going to take on the topic of email deliverability. Below is all the information we have been able to gather to increase your success in making sure you get those emails through to your clients.

What is email deliverability?

Great question! Campaign Monitor defines email deliverability as an email successfully arriving in a person’s inbox. Getting past the email server is one thing–read email delivery–because email providers consider a variety of factors before allowing just anything to enter your subscriber’s inbox.

Glossary of email deliverability factors

Let’s start with a layman’s breakdown of the technical terms you’ll see when discussing email deliverability.

• ESP

An ESP is an email service provider, a platform that sends marketing emails to you. Think MailChimp, Campaign Monitor or our audience platform, Mirabel’s Marketing Manager. They use underlying email deliverability software and give you an interface to send emails and track all sorts of metrics, such as bounce, open, click-through and unsubscribe rates. These companies really care about obeying the laws of the ecosystem because their servers get shut down if you send unsolicited emails to clients and don’t follow the rules of the game. They deal with dozens of internet service providers who are capable of throwing up roadblocks for bad bad behavior, and keeping a good reputation is a big part of the cost of running an email service provider.

• ISP

An ISP, or internet service provider, is a service that provides internet. In addition to providing cable and internet, these companies, like Xfinity, AT&T, Verizon, and Cox, provide users with a mailbox as well. They are part of a large police force that monitors the web for spam. If they see spam from an email service provider’s client, they don’t just block that particular company, they can block all emails from that email service provider. Thus, ESPs have a lot to lose by allowing a customer to send spam out through their service.

• Inbox providers

These are your Gmails and Yahoo! Mails and Outlooks. They simply provide inboxes where all your newsletters, Bed Bath & Beyond coupons and political donation solicitations can live.

• Bounces

Bounces are pretty common occurrences when it comes to email. When your email doesn’t reach your subscriber, it bounced. Because there is a multitude of reasons why your email didn’t make it, bounces can be broken up into two categories: hard and soft.

Hard bounces occur when the subscriber doesn’t exist. This could be because someone signed up for your list with a fake or misspelled email address, but either way, you want to remove that address from your list immediately. If you get a lot of hard bounces, you’ll probably get a warning from your email service provider, so make sure to analyze those hard bounces and remove them for future lists. Even better than that, use an email list cleaning service to check your lists before you send any major campaigns. Email list cleaners are not fool-proof, but they can identify the majority of bad email addresses before they go out and save you a lot of heartache from the internet police. Self-plug: we offer an email list cleaning service called Clean Your List that integrates with our products (Magazine Manager, Newspaper Manager, and Marketing Manager) and prevents you from sending emails out to bad addresses.

Soft bounces happen when a subscriber does exist but doesn’t necessarily get your message because the inbox is full or an automated reply message is in place. You won’t need to remove these subscribers from your list right away unless the soft bounces continue to occur.

• Sender reputation

Think of your sender’s reputation as a credit score. A good reputation lets ISPs and inbox providers know that you are trustworthy and your emails are good to enter the Promised Land that is your subscriber’s inbox. A good sender reputation is paramount to email deliverability.

Sender reputation can be evaluated based on your IP address, which is the unique number attached to your internet-connected device, or domain, which is the unique name of your website that subscribers type in to access your content.

Magazinemanager.com is our domain, for example. The IP reputation is often the reputation of your email service provider’s server, but the domain reputation is solely your responsibility. So, if your provider has a good reputation, your emails can still get blocked by various internet service providers because your domain has a bad reputation. Email Service Providers see this all of the time. Clients call saying their emails are not getting through and think it’s the ESP’s issue. Email Service Providers can show you the reputation of the IP addresses on their servers, which are good, and then show the reputation of your domain, which might not be so good, and the problem becomes obvious.

So, how can you bolster the pristine reputation of your domain? Monitor your email engagement metrics, especially bounce rates and spam complaints. The lower the number, the better for you. Avoid spam traps and blacklists, which we’ll elaborate more on soon. And finally, consider the domain reputation of the links you provide in your emails. Tools like WatchGuard and Sender Score can help you check domain and IP address reputations so you don’t include anything that could potentially get you classified as spam.

• SPF

Not a sun protection factor, but a sender policy framework. Setting this up is essential to protecting your domain from being fraudulently used and subsequently classified as spam. SPFs allow your domain to be connected to a specific IP address. These all live in a directory of sorts called the DNS (domain name server).

When you send an email, ISPs and inbox providers consult the DNS to verify that the email is definitely from your domain. If the IP associated with the sending domain doesn’t match what the DNS has, per your SPF, the email in question will either be rejected completely or sent to the spam folder. This is the number one reason why our clients’ emails do not make it to inboxes.

• DKIM

DomainKeys Identified Mail is an authentication process that boosts deliverability by helping to confirm an email has come from the domain it claims to be from. This is similar to an SPF, but rather than being affiliated with an IP address, a domain gets assigned a digital signature (read: unique encrypted key private to the sender). Receiving ISPs and inbox providers then search the DNS for a public key matching the sender’s private one. If the keys match, the email in question has not been tampered with in transit and is safe to enter the inbox.

• Feedback loop

A feedback loop, in the context of email marketing, is a service that shares–yes, you guessed it–feedback from subscribers with you. When a subscriber marks your email as spam, this is a complaint that, with a feedback loop in place, will be reported to you. While most ISPs and inbox providers offer this feature, you’ll still need to set it up. Luckily, Return Path has covered feedback loops at length.

• Blacklists

This is a list you do not want to be on. Blacklists are collections of domains and IP addresses that have been noted for being spammy. How does one get classified as spammy, you ask? Well, someone could use your domain to send spam emails, which is why an SPF is great to implement. You could also get caught in a spam trap, which I’ll elaborate on next. It’s possible to recover from being blacklisted if it only happened once. If it keeps happening, you have a problem.

• Spam traps

Spam traps are fake email addresses that look real. They’re used by anti-spam companies who offer their services to ISPs to catch spammers and unsuspecting marketers who buy email lists to unnaturally grow their subscribers. The trap usually consists of putting real email addresses that are no longer in use in a place where data-scraping companies would likely find it. They know that you bought this list from a data-scraping company because of they “seeded” spots on the internet with it. It’s pretty foolproof, and your email-scrubbing software won’t catch it, as email-scrubbing software only checks for bad email addresses, not realistic-looking fake ones. Sending an email to a spam trap will get you automatically classified as spam, so just don’t buy email lists. It’s the fastest way to find yourself in an email jail.

How to ensure consistent email deliverability

You’ve put in all this work to make sure your domain(s) and IP address have good reputations. You’ve avoided spam traps and blacklists implemented a sender policy framework and DKIM signature and scrubbed your list clean of addresses associated with high bounce rates. Getting into inboxes is a hefty part of the equation, but the other half is making sure all this effort wasn’t for nothing, that your emails consistently get delivered and if you’re lucky, read.

At this point, what you’ll want to avoid most is spam complaints. They’ll rupture the foundation of your deliverability by attacking your sender reputation. Spam complaints are inevitable, as many people mark emails they don’t want to read like spam, unaware of the negative repercussions this could have on a sender. If you’re guilty of this, try marking individual emails you don’t care to look at as read, or simply delete them. If you no longer want any emails from a specific sender, unsubscribe.

To preemptively combat spam complaints, incorporate the following measures when building your email lists and campaigns:

• Include a double opt-in

Having a double opt-in can help reduce bounces and manage spam, but most importantly, the reinforcement can result in fewer spam complaints. How? A double opt-in means that once someone has signed up to your list, he or she receives a confirmation link that must be clicked to officially receive your messages. It requires a little extra effort from recipients, but by confirming they’re opt-in, they show that they genuinely want to receive your campaigns and are less likely to mark them as spam. Plus, double opt-ins weed out real email addresses from fake ones, as a spam address can’t confirm the second opt-in. Now, you won’t end up on a blacklist for inadvertently emailing a spam address.

• Make the most of your sender names and subject lines

They always say not to judge a book by its cover, but when it comes to emails, subscribers tend to judge a book (email) by its cover (subject line). It’s super important that your sender names and subject lines capture attention in a non-spammy way. For starters, your sender’s name or email address should never explicitly mention “do not reply” because it’s insincere and subscribers may flag this as spam before even opening your message. If you want to emphasize that the address from which you’ve sent a campaign is automated and unable to respond to replies, include a disclaimer in the body of the message. Always humanize your sender. Feature a name with an email address that matches. If I were to send out an email, I’d show up in your inbox as Rachel from The Magazine Manager <rachel@magazinemanager.com>.

For subject lines, don’t use all-caps, RE: or FWD:. Spammers use this tactic often because it’s effective at grabbing attention, but ISPs, inbox providers and subscribers themselves have grown weary of these sorts of subject lines for that exact reason and will classify these messages as spam without a second thought.

• Maintain consistent frequency

If you always send two emails per week, switching to four can negatively impact your sender reputation. Subscribers familiar with your cadence will notice the change and think something unusual is going on, which could result in a spam complaint. Temporary modifications to your frequency for things like holidays, special events or a limited series happen, but ongoing inconsistent sending is what you want to avoid.

• Feature consistent designs that are mobile-friendly

Another place where consistency affects deliverability: your email’s design and content. Your website looks a certain way because it embodies your brand’s identity. Your emails should mirror that identity, too, so subscribers aren’t confused by non-cohesive branding and subsequently mark your message as spam.

Also like your website, your emails should be mobile-friendly. Over 50% of email opens occur on mobile devices, and a lack of mobile-friendliness can result in a spam complaint. Many email service providers optimize for mobile anyway, so there’s no excuse for your emails to not be compatible.

• Include plain-text versions of emails

Have you ever opened an email where the images didn’t automatically load? Same. Not all inboxes are equipped to receive your gorgeous campaigns, which is why you should always include a plain-text version. ISPs and inbox providers will look favorably on your plain-text email because they’ll know exactly what’s inside, and recipients will still get the primary message you want to communicate, diminishing any reasons to mark your email as spam.

• Avoid shortening URLs

If you use external linking in your emails, avoid using shortened URLs. They can be convenient, but they hide a link’s destination, which makes them popular among spammers. Don’t get marked as spam; simply use hyperlinks to link externally and include the full URLs of your outside sources.

• Segment your audiences

There are many ways to go about segmentation, but the gist is grouping together subscribers based on demographic similarities or common interests. You’ll give them the content they really want, and your open rates will soar while your unsubscribe rates plummet.

This is where big data can be good. Target, for example, would never send its entire contact list a promotion for new tennis rackets, because not all of its customers care about the latest in sports equipment and doing so could result in a mass influx of spam complaints. Instead, Target’s email marketers likely use big data, such as past purchases and browsing history, to create a segment of customers who will most appreciate an email about tennis equipment, not mark it as spam, and eventually make a purchase.

• Make unsubscribing simple

An easily accessible unsubscribe method will help you maintain your pristine sender reputation, as subscribers can simply unsubscribe instead of clicking link after link, until the frustration boils over, coming to a head in the form of a spam complaint.

It’s almost too easy for someone to mark a sender as spam–that’s why it happens so often–so you must make the unsubscribing process just as easy. Unsubscribes are much better than spam complaints, as the former won’t impact your sender reputation and ultimately, your deliverability.

Recapping it all

Email deliverability is more than just reaching your subscribers. You could reach your subscribers in the form of spam, but that’s definitely not what you want. You want that coveted spot in their inboxes, and to achieve that, you must take several factors into consideration:

1. Make sure your IP address and/or domain has a good sender reputation so ISPs and inbox providers will let you in.
2. Avoid spam traps by not purchasing email lists. List companies often scrape data from the web and that data may be “seeded” with inactive, fake or bad email addresses. Purchasing email lists and sending emails to people who have not “opted in” to your emails is the easiest way to end up on a blacklist.
3. Check your feedback loops for spam complaints, and immediately scrub those subscribers, as well as invalid, spammy and inactive email addresses from your list to reduce your bounce rates and negative hits on your sender reputation.
4. Implement SPFs and DKIM signatures so ISPs and inbox providers can verify that you’re allowed into the desired inbox.

Once you’re in the inbox, this is how you can make sure your emails take up a permanent residency:

1. Provide double opt-ins
2. Make the most of your sender names and subject lines
3. Maintain a consistent cadence
4. Feature consistent, mobile-friendly designs
5. Include plain-text versions of each email
6. Avoid shortening URLs
7. Segment your audiences
8. Make unsubscribing simple

Yes, sending a successful email campaign requires plenty of effort, but when you consider that email is rapidly becoming the number one way to drive revenue, while also allowing you to truly own your audience, it makes it all worth it.