Email Deliverability – Gmail Case Study

Email Deliverability – Gmail Case Study

As customers, even as marketing professionals, it’s easy to miss the importance of newsletters. Picture your own inbox: you probably get quite a few, but how many do you really click through on, let alone engage with? Odds are, not that many. But like everything marketing, newsletters are a numbers game, which is why you can so easily miss seeing what makes them so effective.

Well, it’s time that we put newsletters to the test- and we mean that literally! This right here is our complete guide to, and our comprehensive study of, newsletters and best practice. We’ve looked in real depth at more than a hundred sites and their newsletter/subscription strategies, to figure out what they’re doing right and what they’re doing wrong. Plus, we’ve boiled down what we’ve found into friendly stats and best practice guidelines—all of which you can find below!

email deliverability

What? Huh? What is it email newsletters are good for? Absolutely EVERYTHING! Say it again!

Newsletters are good for two things:

  1. Creating a steady stream of repeat sales from repeat customers.
  2. Creating, maintaining or increasing brand awareness.

Like we said above, newsletters are a numbers game: so if you have a subscription list 1,000 email addresses long, you’re not going to generate 1,000 sales with one. You won’t even generate 100. In fact, if you’re anything like most E-Commerce stores, you’ll create somewhere between 10 and 40 sales in all.

email conversion rate img

The average conversion rate for a basic newsletter which you mass-send to every single one of your subscribers is going to convert just north of 1%. If you send out a segmented newsletter, you can push that up to 4.3%, with an average order value of £71.59. That’s why in the long run, using a CRM or another email automation tool won’t cost your business money, but make your business money.

If you’re completely new to the idea of segmented emails/newsletters, it’s a simple enough idea. It’s all about sending the right email to the right people. Say for the moment that you’re a teenage boy; it doesn’t matter how many baby shower inspiration newsletters we send you, because you won’t have any reason to open them! Email segmentation is about using your customer data to send those newsletters to the right people on your email list, instead. That way, you aren’t wasting your own time or your customers.

The other great thing about newsletters, as we mentioned above, is that they raise awareness and create interest in your brand. This goes beyond the idea of just making a sale; it’s more about making sure that your site is the first thing a customer thinks of when they need to do Christmas shopping or to buy something for the garden. Think of all the Coca-Cola or McDonalds adverts you see on TV; barely half of them are actually announcing anything new or interesting. The point is just to remind you that they exist, so that the next time you’re thirsty or hungry, that’s what you’ll go for.

So.. I’ve worked on my email marketing strategy, decided to create a suite of email templates and I’m ready to send. Anything else I need to know?

…Well actually yes! Quite a bit. Did you know that even if you’ve got your email ready to go, there’s quite a few factors which can prevent your email from even reaching your subscribers main inbox? It could go to your spam folder or even a sub-email folder like promotions if you’re using gmail.

Factors Which Can Result in Your Email Being Sent to Spam

Email on Acid, a brilliant email design and testing tool has a really great comprehensive article which describes affecting factors such as words with all capital letters, lots of exclamation marks, all image emails and many more factors. You can find the full article on this here.

So we wanted to not just give you the facts, but give you an actual case study to show you the impacts these factors have.

About the Gmail Case Study

Aims of the Case Study

  1. Find out how many websites offer email newsletters.
  2. Report back on any factors which affect email deliverability and in particular common factors that result in emails being sent to spam.

About the Email Newsletter Sample Data

To keep it fair we only analysed websites that were ecommerce and that fell into the electronics consumer supply category – so these were websites that sold products like: electronics, appliances, kitchen appliances, mobile phones, buy fridge, buy laptop, buy camera, hifi systems and headphones. We also tested a mix of large well known brands as well as smaller companies too to keep it fair.

Large well-known brands included the likes of Homebase, Very and HP.

Smaller brands included Clifton Cameras, PrinterBase Ltd and Pro Audio Systems.

What We Did

  1. We created a gmail account
  2. We tested over 100 websites to see firstly which websites offered newsletter signups.
  3. Of the website’s that offered newsletter signups, we tested them using the same email address to see exactly how their newsletter signups and deliverability held up.
What Did We Find Out in the Email Newsletter Case Study?

Out of the 103 websites we analysed, only 37.86% actually sent out an email newsletter. We found this much lower than what we expected from the E-commerce category.

Also only 1 email newsletter we subscribed for went to spam out out the whole sample. And their website newsletter signup box actually said “Please check your spam box.” So even they knew their email deliverability was bad!

gmail promotions graphic imgSo on the surface there really wasn’t much we could show for this. BUT. WAIT! There was… Actually over 53% of the emails newsletters we subscribed to went to the gmail promotions tab. And granted this isn’t some type of spam folder, but it’s a secondary folder where often junk offers get placed.

If you’ve never used Gmail before, it automatically separates emails into different folders: Primary (like a regular inbox), Social, Promotions and Spam (as well as less commonly used ones like Updates and Forums). Gmail accounts are automatically set up this way when you open one, although you are free to change it if you’d like.

The reason we picked Gmail is that it’s enormously popular and also because the folder that an email goes to determines how quickly the end user sees it. This means that a newsletter that gets through to the Primary folder is going to get a higher open rate and CTR than one that Gmail decides is fit for Promotions or, worse yet, spam.

So What? Big deal! I hear you say…

Well actually… this is a very big deal. This is because if one of your customers just signed up for an email newsletter they probably already have strong expectations for your email. Like:

  1. A confirmation email to be sent to their main inbox (not promotions or spam).
  2. The confirmation email should arrive within a reasonable amount of time (minutes not days!)
  3. An email newsletter to be sent out (after subscribing) – Yes this is an obvious one but you’d be amazed by how many companies do not do this.
  4. Receive relevant content to what they have subscribed for. Don’t bombard them with promotions (at least not to start with) if they’ve not especially signed up for this.

If the email poorly delivers (excuse the pun) on any of the above factors, it’s likely to have a huge impact on how that customer perceives your brand. For example:

  1. If email delivery is slow – this could suggest that your actual product delivery and dispatch might also be slow.
  2. Not sending out a followup newsletter – the customer could read this as issues to do with the quality of your product or service.
  3. If you bombard a customer with irrelevant emails – they may feel like you do not care about them and you’re only concern is to generate extra revenue (no matter if there is a danger of loosing or annoying your subscribers).

That’s why it’s absolutely paramount that you review your email campaign process on a regular basis. And if your email has ended up in the subscribers Gmail Promotions tab, it’s possible that they will be feeling like all or some of the above scenarios (until they find your email).

So What Did We Do About it?

We carried on the analysis but instead of looking at spam related factors we looked emails that went directly to our inbox VS emails that went to the Gmail Promotions folder.

What Did We Test This Time Around?

To dig down and find out exactly what was sending the emails to promotions folder instead of the main inbox, we decided beforehand to test for a number of metrics. For each one of our signups, we looked at the following:

  • Number of image elements
  • Number of words
  • Percentage ratio of image elements to word count
  • Whether or not there was a reply email
  • Whether or not the reply email or sender email contained a “no reply” or “do not reply”
  • Subject line character length
  • Encrypted vs. not encrypted emails
  • Number of links
  • Total number of sales words (deals, offers, shop, free, delivery, sale, sales, clearance, coupon, discount, promo code, promo, buy, purchase, discount)
  • Use of sales icons (e.g. £, % etc.)
  • Time signed up vs. time upon receipt of first email
Statistical Analysis & Results of Emails Received
What We Analysed Inbox Promotions Spam
The percentage split of where emails were delivered
inbox, promotions or spam
43.59% 53.85% 2.56%
Email subject line length
total average of all emails
35 characters 39 characters 36 characters
Reply-to email field set? 17.65% 57.14% 0%
“no-reply” or “do-not-reply” found in reply email
[email protected]
[email protected]
0% 14.29% 0%
Sender from-email address contained “no-reply” or “do-not-reply” 23.53% 9.52% 0%
Total percentage of emails received which were encrypted
70.59% 85.71% 100%
Total percentage of emails received which were not encrypted 29.41% 14.29% 0%
Average number of image elements 5 9 1
Average number of scaleable words
Scaleable words are words which can be read and analysed by a web robot. Words which are not scaleable are often contained within images and although they can be read by a human when they view an image, they wouldn’t exist to a web robot.
111 195 113
Average image to text ratio
images ÷ scaleable words
5.27% 4.51% 0.88%
Average number of links 10 18 3
Average mention of sales words
deals, offers, shop, free, delivery, sale, sales, clearance, coupon, discount, promo code, promo, buy, purchase, discount
3 5 1
Average use of sales words to average text ratio
sales words ÷ scaleable words
2.70% 2.56% 0.88%
Average use of sale symbols within emails
0 2 0
Key Elements Which Affected Email Deliverability
  • “no-reply” or “do-not-reply” found in reply email
  • Average number of image elements
  • Average number of links
  • Average mention of sales / promotional words :
    deals, offers, shop, free, delivery, sale, sales,clearance, coupon, discount, promo code, promo, buy, purchase, discount
  • Average use of sale symbols (£,% etc)
What to Learn From This?

email marketing tip image

  1. If your sending a first email, especially if it’s a confirmation email, make sure you do not sure too many promotional wording within it. You might look to setup your email subscriptions by implementing a double opt-in method. This means that when a subscriber submits their email address into your newsletter subscription form on your website, they will receive an email asking them to confirm their subscription to the newsletter. Often this is done by clicking a link or by submitting a code. Again if this goes to promotions or worse the spam folder, you’re likely to be missing out on subscribers.
  2. Make sure to send out email confirmations / your first email, within a reasonable period of time. If you’ve left it until days or weeks after, a subscriber might even forget that they’ve signed up to your newsletter and quickly unsubscribe. If this seems like a daunting manual process for you, you might want to look into choosing a CRM system that offers marketing automation.
  3. Try not to use “do not reply” or “no reply” as your sender or reply to email. It sounds obvious but not only will this affect your email deliverability, even if your email does make it to a subscriber’s inbox, it doesn’t give a great first impression of your brand and it might look like you just don’t want to hear from your customers.
What About Not Sending Newsletters?

Now, not every site we came across actually had the option to sign up for a newsletter. There are normally one of two reasons why you can’t find a sign-up form for a newsletter on a business’ site:

  1. They don’t actually have one.
  2. They send the newsletter by default to every person who creates an account through the site, not just to anybody who signs up through a form.

ecommerce email newsletter graphic image

Of the websites we selected, 58% offered a user the chance to sign up for a newsletter through a dedicated form, and 42% didn’t. In fairness to the websites that don’t offer a sign up form, there are a few good reasons for this:

  • First, having the newsletter tied in with opening up an account means that you get far more people on your mailing list. That can only be a good thing!
  • Second, having people open up a whole account- as well as providing all the details that come with that- means that you have more data to work with than if somebody signed up with an email address alone. More data means more opportunity for segmentation, which we talked about above. The more segmentation, the better you’re going to convert emails into sales.

By contrast, there’s a really good reason to actually separate your newsletter from your general signup. So, with a CRM the point is to sort the wheat from the chaff, whether you’re talking about lead scoring, email segmentation or identifying incorrect customer data. Now having every single account holder on your mailing list is going to look great in terms of numbers, but you won’t be converting as high a percentage per emails sent as if you only sent your newsletter to people who’d expressly signed up for it. That’s just a fact of life. The truth is that targeting starts at the source; you’re making a rod for your own back by including anyone and everyone’s email address in your list if you’ll only have to filter them out later because they don’t engage.


So there you have it – email marketing has a lot of elements to cover for it to be effective. Remember what your email looks like and your content is obviously key, but don’t forget factors that affect deliverability. Getting the mix right can seem like a daunting task but providing you have the right email marketing software and you’re regularly comparing your email performance statistics (open rate, link clicks etc), you should easily grow your subscriber list and most importantly – achieve a fantastic return on investment.