Having good email deliverability is one of the most important steps you can take towards creating a successful email campaign. Without it, it’s likely that a significant proportion of your emails will be filtered into spam folders by the major ISPs such as Gmail, Outlook and Yahoo.

To put it bluntly, if you are not managing your email deliverability, you could be spending valuable time and resource on building email campaigns that are not being seen - severely reducing your email programme’s ROI.

At Jellyfish Connect, we keep a keen eye on a number of key deliverability indicators, to ensure we maintain strong email deliverability. Primarily, the indicators we keep a watch of are:

• Delivery rate - this is simply the percentage of emails sent which are delivered.
• Inbox placement rate - the percentage of emails delivered, that land in the inbox.
• Spam placement rate - the percentage of emails delivered, that land in spam.
• ISP complaint rate - the percentage of contacts who report an email as spam.
• Soft bounce rate - the percentage of emails temporarily bouncing.
• Hard bounce rate - the percentage of emails permanently bouncing.
• IP reputation - do ISPs consider our IP address to be trustworthy?
• Domain reputation - do ISPs respect our email domain?

Keeping track of these key email deliverability indicators with our magazine.co.uk email program has brought us great results, with an average delivery rate of 99.6%, and an average inbox placement rate of 93%, whilst both our domain and IP reputations are regarded as high by Google Postmaster (a useful tool that we’ll discuss later on!).

Here, we share our 6 tips to help you build and maintain your email deliverability:

1. Authenticate your emails
It’s really important that your emails are authenticated through the DKIM, SPF and DMARC frameworks. Email authentication acts like a digital signature - protecting your brand from spoof senders and phishing, making it difficult for fraudsters to send an email pretending to be from your brand.

Email authentication will really help your email deliverability too. All major ISPs such as Gmail, Yahoo and Outlook look for email authentication when deciding whether an email should be delivered, to protect their users. If you do not have your emails authenticated, it’s likely ISPs will mark them as spam, or even block them entirely.

To check whether your emails are authenticated, you can use MXToolBox. Simply enter your email domain, and MXToolBox will analyse your DMARC, DKIM and SPF records. If you find your emails are not fully authenticated, contact your email service provider or ask your web development team for help.

2. Use an inbox placement tool
When you read your delivered rate, it is simply a measure of just that - the percentage of emails you sent that were successfully delivered. However, this does not necessarily mean your emails are landing in the inbox or avoiding spam folders. It could be possible to have a 100% delivery rate, but also a 100% spam rate!

To understand whether your emails are successfully making the recipient’s inbox you need to use an inbox placement tool, such as 250ok or Glockapps. These tools will provide you with information on how many of your emails are landing in the inbox, promotion tabs or spam. You’ll also see which ISPs are causing you the most inbox placement problems, such as Gmail, Yahoo or Outlook. Once you have this information, you’ll have a greater understanding of how ISPs rate your email campaigns, and where you might need to improve.

3. Send email to your most engaged data only
ISPs such as Gmail filter emails based on thousands of signals to decide whether an email should be placed into spam, including engagement metrics such as open rates, click-through rates and complaint rates. So it’s vital to keep your lists clean by removing any chronically unengaged data.

How you do this will depend on the intricacies of your business, as all lists are different. However, a good start is to consider your send frequency. For example, if you send multiple emails each week, it could be a good idea to stop sending to any contacts that have not opened or clicked on one of your emails within the last 90 days. If you only send one email a week, you may decide to remove contacts who haven't engaged within 180 days.

At first, it can feel quite counter intuitive to reduce the size of your lists, but it is much more valuable for your most engaged customers receive your emails, than to send to huge lists which reduce your reputation amongst ISPs, and cause your emails to be delivered as spam. Reducing your list size in this way will also reduce the cost of your email programme - after all, what’s the point in paying to send emails to people who are not opening or engaging with them?

4. Implement a re-engagement programme
Once a contact reaches a certain point in time without having engaged with your emails, it can be effective to enter them into an automated re-engagement program. For example, if you decide on 90 days as the point to stop emailing unengaged contacts, give them one last chance to stay on your marketing list with a re-engagement email.

This email should be quite different to your usual campaigns, paying particular attention to the subject line, so it really attracts their attention.

Any contacts who still do not engage with your emails can be removed from your future promotions to protect your deliverability.

5. Utilise Google Postmaster Tools
Google Postmaster Tools is a very handy tool which gives you visibility of how Google’s Gmail service rates your emails. Think of it as the email equivalent of Google’s Webmaster Tools service (now coined Search Console).

Key information that you’ll receive includes:

• Spam rate - you’ll see a dashboard, displaying how many of your Gmail contacts flag your emails as spam when delivered into the inbox.
• IP and domain reputation - you’ll be given a rating from bad to high, indicating whether your emails are more or less likely to be marked as spam. Remember, however, these are just two of thousands of indicators that Gmail will use to determine whether your email is spam.
• Authentication records - Postmaster will show you your DKIM, SPF and DMARC authentication success rate. Useful to regularly ensure nothing has gone wrong with your authentication.

Postmaster Tools will also show you whether your emails are being successfully encrypted, whilst also flagging any delivery errors.