By Luke Knight

As social reach declines and competition to grab consumer attention online increases, marketers are focusing on the channels they know work. Email is having a renaissance.

According to Marketing Week, email generates around £29bn (yes, billion) retail sales annually. A whopping 73 percent of marketer’s rate it as the number one digital channel for ROI.

Figures like this are the reason many brands are doubling down on their email marketing efforts. Marketers are honing their subject line skills, crafting the perfect call-to-action, and getting tech happy with an array of smart automations.

If this sounds like you, you’re in the right place. Before you forge ahead with your email strategy, let’s make sure it’s built on strong foundations.

Why does email deliverability matter?

Email deliverability is the percentage of emails you send that actually reach your recipients inbox.

As an email marketer, deliverability is the most crucial metric you can measure. If your emails don’t get delivered, your efforts were wasted. Your open rates, click rates, and conversions all depend on your emails actually being received.

Monitoring email deliverability—and taking measures to improve it—is fundamental if you want to win at email marketing.

Factors that affect email deliverability

Much like Google’s algorithms, no-one knows the exact formula Internet Service Providers (ISPs) use to decide which emails get delivered. But we do understand some of the key things they look for.

So, which factors affect whether your email makes it into your recipient’s inbox?

The quality of your email list

One of the most basic things ISPs look for is how your recipients respond to your emails. This is determined by the quality of your email list. In other words, your data and how you collect it.

On the most basic level, a quality email list is made up of people who want to receive your emails when you send them. You need to ask people whether they want to hear from you and how frequently when they sign up.

Your reputation as a sender

Another thing that determines whether an ISP will deliver your emails is your reputation as a sender.

A large part of your reputation hinges on how well people engage with your emails. But there are also some other factors at play. These include:

• Send volume and consistency: ISPs look for sudden spikes in the volume or frequency of email sends as this tends to indicate spammy activity. Be sure to keep a fairly consistent volume and frequency so this doesn’t affect your deliverability.
• Bounces: ISPs monitor your soft and hard bounce rates. Hard bounces happen when an email address isn’t valid. Soft bounces mean the email is correct but the message may be too large or the mailbox might have been full. High bounce rates can mean your email list needs cleansing and can reduce deliverability.
• Being marked as junk: This is the email equivalent of receiving a complaint. Even a few recipients in your list marking your emails as junk may impact your deliverability. Your emails should be relevant and wanted. If they aren’t, you have a problem.
• Spam traps: These are dodgy email addresses that are set up to catch out email marketers with questionable methods of collecting email data. If you end up with these on your list, your ISP may start sending your emails to junk.
• Blacklists: If the IP address you send from has ended up on a blacklist this is bad news for your email deliverability. This would only happen if emails from your IP address have hit spam filters or frequently been marked as junk.

Your content

ISPs are likely to send your emails to junk if they consider your content to be poor quality. But which factors affect this? Here are some warning signs ISPs look for when they judge the quality of an email:

• Links to spammy websites: If your email links out to a dodgy website, that indicates your email is not a quality one. Double check third party sites using blacklistalert.org before you link to them.
• Use of link shorteners: ISPs aren’t a fan of link shorteners in email as it makes it seem like you’re trying to conceal a URL. This indicates poor quality as it’s something spammers might do.
• Attachments: Getting someone to open a dodgy attachment is a spammer’s dream! Don’t let ISPs suspect that this is what you’re up to. Avoid attachments and link to content instead.
• Text to image ratio: Overuse of images seems spammy. Make sure your text to image ratio is around 60/40 to keep ISPs happy.
• Unsubscribe: Spammers love to keep recipients locked in to their dreadful emails. And when they do, people mark their emails as spam. Don’t let that be you. Never hide your unsubscribe link.

ESP infrastructure

There are some technical factors that your email service provider (ESP) controls that affect deliverability. You can read more about them in our deliverability support guide.

Long story short, choosing a reputable ESP ensures your emails are sent through a platform that ISPs view as trusted. This affects deliverability.

Seven ways to improve email deliverability

Now you know some of the factors that affect email deliverability, let’s discuss what you can do to improve yours.

1. Keep your email list clean

The first thing you can do to improve email deliverability is to look after the hygiene of your email list. To keep a clean list:

• delete contacts that are hard bouncing
• delete contacts that remain inactive for long periods
• remove those who unsubscribe straight away
• check people’s preferences every so often
• re-engage subscribers before they fully lapse

2. Set expectations of contact

Our second top tip to improve email deliverability is to set expectations of contact. This is particularly relevant in light of GDPR.

The way you ask for consent needs to be freely given, explicit, and granular. This means someone needs to consciously opt in to the specific ways you plan to contact them.

Being transparent when you obtain consent to email someone sets expectations for your relationship. It means, for example, that they won’t be surprised when you email them about new product lines every Tuesday. Because you told them you would.

When people know what to expect and want to receive what you’re sending, they are more likely to open and read your emails. ISPs monitor this and use this to decide whether future emails you send are destined for a recipient’s inbox or spam folder.

Further reading: How GDPR Will Impact Email Marketing

3. Use a preference centre

Setting expectations from the get-go is important, but people’s preferences may change. To keep your emails aligned with what your customers want, set up an email preference centre.

A preference centre is a landing page on your site that people can easily access to change their email preferences. For example, they could untick receiving certain emails. Or they could change how often they hear from you.

Having an email preference centre improves engagement, and therefore deliverability.

4. Send from a branded domain

This one’s super simple but of vital importance. Ensure your emails are sent from a domain that’s clearly owned by your brand.

If someone is expecting your email, help them see instantly that what they just received is from you. Domain is the quickest identifier.

5. Send a welcome campaign

Sending a series of welcome emails is a great way to set the tone for a positive and engaged relationship with your subscribers.

Use your welcome series to tell them what to expect from you and why they should open your emails. Get them invested from the start and you should see this reflected in engagement.

6. Personalise your customers’ experience

Long-term engagement can be achieved by offering customers an outstanding experience that they want to keep repeating.

To do this well, you need to get personal. Use marketing automation to set up workflows that are triggered by specific actions your subscribers take. This is a form of behavioural marketing that ensures your marketing stays timely and relevant.

7. Re-engage sleeping subscribers

Our seventh top deliverability tip is to re-engage sleeping subscribers.

Identify segments who have not opened or clicked for a while and send them automated re-engagement campaigns. Remind them why they signed up and show them what they’re missing.

This is an effective way to keep engagement levels up and improve deliverability.