Email deliverability has been a challenge that even the most seasoned marketers combat on a regular basis.

There’s probably nothing more painful than realizing that the email you had carefully written and designed never reached the subscriber’s inbox – it was likely pushed into the Junk or Spam folder where it won’t be ever read.

Email deliverability – the ability to place emails into your subscribers’ inbox as intended – is the key metrics that marketers try to get right. If your email is not placed where it can be read, everything else is useless.

The Spam Filter

Despite everything you do from your end to get an email placed in the inbox of the recipient, it’s the mailbox provider that takes the final decision on where your email should be placed: the Inbox or the Junk folder. That means if you’re focusing on improving email deliverability, you should understand emails from the point of view of the mailbox provider.

All mailbox providers have a spam filter – a mechanism that blocks incoming spam. Every single inbound email has got to pass through the spam filter of the mailbox provider, so avoiding the spam filter, by whatever means, is impossible. However, by following email marketing best practices, you can convince the spam filter that the email it has received from you is not spam.

Factors Impacting Email Deliverability

A ReturnPath study suggests an average of 13.5 percent of all incoming email is placed in the Spam folder. You don’t want your email to be one of them.

Different spam filters use different standards to keep unwanted emails from reaching the inbox of the recipients. However, there are some common practices that all spam filters follow.

5 Issues That Hurt Your Email Deliverability and How To Correct Them

Below is the list of issues that impact email deliverability and ways by which you can work on each to significantly increase your deliverability rates.

  1. IP address reputation
  2. Sender Reputation
  3. Email subject line and contents
  4. Email Service Provider – your automation partner
  5. Email list quality

IP Address Reputation

An IP address is a numerical label unique to each device that’s connected to any computer network using the Internet Protocol (IP) to communicate over a network. IP address reputation is the extent to which the IP address (actually the sender using the IP address) has acted responsibly while sending emails.

Spam filters judge incoming emails on the basis of, among other characteristics, the IP address reputation of the sender.

While sending email campaigns, you can either use a shared IP or a dedicated IP.

A shared IP is where multiple senders use the same IP address as you do, to send their emails from.

The reputation of a shared IP address is the aggregate of the reputation of all those who’ve used the IP before you do. So sharing an IP also means sharing the reputation of everyone else using the same IP. Poor practices of any of the previous sender will negatively influence your email deliverability.

A dedicated IP, on the other hand, is one where you are the only user of the IP address.

Hence the reputation of a dedicated IP is influenced only by your own practices, since you are the only user of that IP. That gives you absolute control over the IP reputation.

How You Can Get Your IP Address Reputation Right

If your volumes are small, using shared IPs helps you control costs. But as your sending volume grows, you’ll need to move to dedicated IPs.

When you begin using a dedicated IP it has no previous history. So it has no reputation, good or bad. Your task will be to build the IP reputation by following email marketing best practices.

You can’t immediately send a large number of emails the moment you get a dedicated IP; you’ll have to gradually increase the number of emails you send (a practice called throttling), as mailboxes slowly start recognizing you as a responsible sender.

Begin by sending to your most engaged subscribers. That way, you get a much better open rates and a zero bounce rate. This sends positive signals to the mailbox provider regarding your reputation.

2. Sender Reputation

Sender reputation is a composite result of the IP address you send emails from, your domain reputation, SPF (Sender Policy Framework) authentication, the bounce rate of your campaigns till date, subscriber complaints, engagement, whether (and how many) spam traps sit on your subscriber list and other factors.

Email engagement – what subscribers do when they receive your email – is key. Subscriber actions that suggest they are willing to interact further with you, like opening the email, reading the email, clicking on a link, following a call to action, forwarding the email and so on is considered ‘good engagement’. Actions like not opening the email or deleting the email without reading it is considered ‘poor engagement’.

How You Can Improve Your Sender Reputation

Keep new subscribers in a separate list. Add them to the regular list only after new subscribers respond to your double opt-in. Or add them to the regular list only if the welcome email doesn’t show a hard bounce.

Maintain the right frequency of emailing to subscribers. Long gaps between emails raise the chances of valid email addresses being converted into spam traps. If you email to your subscribers at irregular intervals, they might forget you and are more likely to mark your incoming email as Spam.

Have a plan of action to handle inactive subscribers. Give it your best shot to win them back. But once their inactivity crosses a certain threshold, stop sending them emails.

Finally, never use purchased lists.

3. Email Subject Line and Content

Nearly 60% of the email traffic worldwide is spam. That suggests spammers are getting aggressive, so spam filters need to stay a step ahead.

One way spam filters identify spam is the email content. Poor grammar and high-risk words like “Free” and “Easily make $$$ online” are some of the first things that make your email look suspicious. Other content that looks suspicious to spam filters includes weight reduction, body enhancement and related pharmacy products.

An all-caps subject-line is almost a guarantee your email won’t get past the spam filter. Moreover, subject-lines with too many exclamation marks is another indicator the mail is spam.

Earlier, emails with shortened URLs in the content were commonly red-flagged; today instances of a shortened URL being red-flagged are a lot less frequent, thanks to its heavy use in social media platforms like Twitter.

Messages that contain only a link or only an image are widely treated as spam.

How You Can Get This Right

Run your email draft through the Spam Check feature Benchmark provides. It gives you an excellent feedback on whether you need to improve your content.

Build a compelling Subject Line. If the subscriber doesn’t like the Subject Line, she’ll likely delete your email without opening it. Mailbox providers, especially Gmail, believe that when recipients delete your emails without opening them, recipients are not interested in your email – a sign you’re sending spam! Over time, your subsequent emails to the same recipient may be pushed into the Spam folder.

It’s best to use clickable keywords in place of lengthy URLs.

Make sure the Unsubscribe link is clearly visible. This may sound a bit counter-intuitive but it works. When recipients can’t find the unsubscribe option easily, they tend to mark the email as Spam!

4. Email Service Provider (ESP) – Your Automation Partner

Select your ESP on the basis of their experience and technical competence, and not some tall claims. For instance, claims by ESPs about overnight improvement in your deliverability rates when you switch to their service from elsewhere are mostly too good to be true. Actually, something opposite is equally likely to happen!

Remember, when you switch ESPs, you are also switching IP addresses. So when the recipient mailbox providers notice you’re suddenly sending from a new range of IPs, they will, rightfully, turn cautious and may place fewer emails in the inbox than they did with the older IP address.

If your new ESP doesn’t understand the importance of throttling, the recipient email box provider might actually push more of your emails into the Spam folder.

How the Right ESP Matters

Choosing the right email marketing partner is more than half the job done.

The right partner will have most things figured out for you. To begin with, they have the right technology in place that can handle hundreds of thousands of emails.

They can, for instance, help you maintain segmented email addresses lists, based on the engagement patterns or interests of the subscribers.

You can also set a variety of subscription options. For instance, instead of losing your subscriber entirely, you can let her choose the frequency of her subscription: a weekly newsletter, a fortnightly compilation or may be a monthly digest.

Finally, a good ESP will have strong measures in place that will have you covered. For example, even if you’ve opted for shared IPs, you can be sure the IP reputation has been maintained at optimum levels by your ESP.

5. Email List Quality

One of the factors influencing the deliverability rates of your emails is also the one you can swiftly act upon: bad email addresses.

Maybe there was a typo when the subscriber keyed in the email address while signing up, maybe the subscriber knowingly entered a wrong address, maybe the subscriber is using a disposable address…Reasons like this lead to your list containing a number of email addresses that are not safe to send emails to.

Sending campaigns to these addresses lead to bounces, poor or no engagement (if the address is role-based or disposable), or complaints. For instance, BenchMark notes sending emails to role-based addresses results in high complaints. Poor list hygiene, therefore, influences email deliverability.

How You Can Deal with Bad Email Addresses

Consider double opt-in. After the subscriber signs up, send them a confirmation email, asking them to click upon a link to activate their subscription. Subscribers who do not follow this action do not receive further emails.

Next, improve your list-building practices. When collecting email addresses manually, e.g. when your team is writing down addresses, spelling errors are most likely to creep in. While collecting email addresses online, use an email verification API service to validate the email address at the entry point, such as signup forms or applications, before the address gets added into your subscriber list.

Use an email verification service to verify email addresses of all your subscribers. It is strongly advised that you validate email addresses at least once a year.

These, by no means, are the only steps you can take to improve email deliverability, but these are some of the most significant ones. Wish you great success in your email marketing!