Everything you need to know about email deliverability and open rate

Heads up: this is a long (~5000 words) blog post so I’ve added topic headings in the list to the left with the key points from each topic. The list will also contain anchors links that will allow you to jump back and forth to read the content as you wish or to read only what is interesting for you (I think all of it is interesting, but then again I’m a bit of an email-geek).

Before we start, let me say a few words on why email deliverability and high open rates are key to all email outreach and how it impacts campaign performance.

Consider the following:

Any email that is not delivered into the inbox of the intended recipient will not be opened. Stronger still, even the subject line snippet of it will not be seen by the intended recipient. Effectively, those prospects are not part of the overall potential of the campaign.

Let’s say that you targeted 1000 prospects and your open rate (due to a variety of reasons) was 30% (very close to the industry average). What that means is that from the 1000 only 300 will actually get to read your content and the other 700 will remain oblivious to who you are and what yo do. Furthermore, since only 300 will actually view your content only they have any chance to reply to you so whatever amount of replies you get will be from those 300 prospects that viewed your message.

Now let’s say you had 15 positive replies so 1.5% (15/1000) of the campaigns total prospects pool – we call that prospect to positive reply rate. The same 15 positive replies can also be expressed in open to positive reply which in this case is 5% (15/300).

Now imagine that you made bunch of improvements and pushed that open rate by 30% to 55% (right at the center of our open rate spread of 40-70%). Assuming you didn’t use click-bait tactics to increase that open-rate, and all other things being equal, you will get the same open to positive reply rate (5%), meaning you will get .05 * 550 = 27.5 positive replies. Even though your open to positive reply rate stayed the same, your prospect to positive reply rate went from 1.5% to 2.7%.

Open rate is the first measure of success (assuming you’re not using it as a vanity metric or using click-baiting tactics) that you need to keep in check. Don’t settle for 30%, when we know that 40-70% is quite common when done things the right way.

Okay, so now that you are with me on the importance of deliverability and open rates. Let’s dive really deep into the factors that impact open rate.

Firstly, deliverability and open rate are not the same thing. They are closely related where deliverability strongly influences open rate (not the other way around). Further in this article I list a set of those factors however there are some that won’t make that list because they are simply random or cyclical. One such factor is out of office or auto replies which may be higher in holiday periods than in peak times.

The following list may be longer but in my experience of having overseen 1500+ campaigns of hubsell customers, I feed these to be the usual suspects. They are all important, the order that I listed them in is not any indication of the same.

1. Bounce rate – a lesser known but a greater cause of low open rates

2. Sender’s email – kind of a big-deal if you want to have one-on-one conversation with your prospects

3. Recipients’ email – anything other than the direct corporate email address is a sub-par strategy

4. Subject line – say in a few words in the subject line what you say in 100 words in your email and don’t do click-baiting

5. Message copy – make it valuable, personally relevant and conversational (not marketing oriented), you want to start a conversation not close a deal

6. Sending schedule – too much too fast leads to too little too late when looked through the lens of positive conversion

7. Target market – back to the drawing board with who you should be targeting in the first place

8. Being human – I know you are not a robot (right?), but often times when we have the ability to deploy automation the human aspect is pushed away

Note: For tech set-up of our mailbox and domain there will be a separate blogpost on DKIM, SPF and DMARC record creation and best practices.

Right off the start, let’s note that there are two types of bounces, ‘soft’ bounces and ‘hard’ bounces. A hard bounce represents an email being sent to a wrong and non-existent email address resulting in a delivery failure, whereas a soft bounce can happen for many reasons other than the wrong email address.

Let’s talk about them in the order of less severe to really severe.

Soft bounces

Soft bounces can occur for various reason even if the email is correct, a few examples of soft-bounces are; message being rejected because your domain rating is too low, or because the inbox of the recipient is full, or your DMARC record has a very rigid policy, or the recipient’s server setup auto rejects or forwards messages automatically based on some conditions. The list continues. The impact of soft bounces is not really as detrimental as a hard-bounce.

All bounces, regardless of whether they are soft or hard, will lower the overall success of your campaign by shrinking the overall potential over your dataset. Consider the following example: You mailed 100 people but 5 bounced so only 95 of them actually received your email and therefore have a chance to read your email, so in essence the overall potential was shrunk by 5%.

Hard bounces

Hard bounces go a step further in causing damage to your overall email marketing efforts which is why it’s important to keep the bounce rate below 5%, which we have found to be well below the line that is dangerous.

Hard bounces impact the domain health and the spam rating of your subsequent emails. Basically, the recipient’s server will considered a hard bounce as a negative factor and the higher the bounce rate the more point will be removed from the domain rating of the sender’s email address.

Let’s consider the following example, you mailed a 100 prospects from which you had the wrong email address for 15 of them, so in this example you had 15 hard bounces. The consequences of those 15 hard bounces are that, just like with soft bounces, your data’s overall potential was decrease by 15%. On top of that, when your email service provider sees that you are using addresses that are incorrect they will make the assumption that your email data quality is low. Each hard bounce will negatively impact your domain’s reputation, so if you have a high bounce rate for long period you can do serious damage to your domain’s reputation.

Bounce management

Making sure that your bounce rate stays low (lower than 5%) is very important for maintaining your domain reputation and keeping open rates high (between 40-70%).

So here are a few key things to remember:

• Ask your data provider what the estimated bounce rate is (in hubsell’s case it is less than 5%) and if the bounce rate is too high consider another provider.
• Monitor your campaigns and pause/stop the campaign if you’re hitting greater than 10% bounce rate.
• Make sure that bounces are recorded / marked correctly as sending a follow-up email to a bounced email is equally bad as sending the first email, and it is totally avoidable.

So let’s quickly look at the different settings which are possible (there may be more but they are not common).

Sender’s email setting types

• You can send emails from a third party server which is typically the case with services like SendGrid and MailChimp etc.
• You can send email from your outbox but under an alias, e.g. let’s say that my email address is ‘rick.sanchez@hubsell.com’ however I have an alias for outbound emails only which is ‘rick@hubsell.com’ – keep in mind that aliases are not separate users in your email service provider setup, they are merely a different email address used by the same user.
• You can send email from your primary mailbox.

Let’s discuss each one by one.

Third party server sending

While third party servers are valuable for use-cases such as newsletters to subscribers, massive mailings and e-commerce drip campaigns, they have limited usability in the world of cold outreach. There is a very good reason for that, cold outreach needs to be or at the very least seem to be one-on-one, a requirement that mass-mailers and third party senders cannot fulfill.

When you use a third party server to send your emails the details in your message indicate that it is mailed by and signed by certain domains. See image below:

Email Snippets for users

The information attached to the message is checked by the receiving server where it will give your message a rating. When the message is sent from a third party server the rating given to it is lower than when the message is sent from your mailbox directly. A low rating means a lower inboxing-rate, or conversely the higher rate means your message ends up in the spam folder.

Aliases vs unique mailboxes

An alias is an email that is not a separate user but rather shares the inbox of another mailbox, e.g. john.smith@hubsell.com and js@hubsell.com can belong to the same person however one of them is the user and the other is an alias attached to the user. Alias email addresses are not considered as full mailboxes by the recipients servers, however not as detrimental as third party servers, they are still less ideal compared to your primary mailbox for doing cold outreach.

Your primary mailbox has many strong points, firstly it most likely has a longer history than your alias created for the sole purpose of doing cold mailings. Secondly, a primary mailbox has incoming mails from your colleagues, your prospects and your customers, so there is a bigger proportion of email traffic coming in comparison to an email that is created for the sole purpose of sending cold emails.

There are three main email types that you can target when doing your cold outreach:

Corporate email – john.smith@domain.com
Role-based emails – marketing@ or info@
Private emails – john.smith@gmail.com

Every time you send an email I highly suggest you to target corporate emails.

Why role-based emails aren’t a good idea

Role-based emails are something both our customers and us don’t use because a lot of times these emails can be managed by more than one person. If you’re trying to target a specific decision maker and somebody else reads the email instead, it won’t be the best fit for them according to the dynamic placeholders that you used.

Also, this might increase the chances of your email getting a soft bounce, which, as we have seen before, is a metric that we want to keep as low as possible to keep our campaign potential high. To top it off, role based emails have too much noise because they are they easiest to be found and therefore receive a high volume of emails.

Why private emails aren’t a good idea

So, if role-based emails are not the ones we should use, then the next logical step would be to send the campaign to the target’s personal email. Unfortunately, this is not the best move either. First, let’s clarify what a personal email is: a personal email is the one that has attached an ending with a freemailer like @gmail, @yahoo, etc or on another paid/hosted server not meant for business. Usually private emails are free email accounts that the recipient might use for their personal affairs.

It’s never a good idea to email private email addresses because the recipients will feel very intruded upon, the content of your message is not relevant to them personally, and according to GDPR it is not legal in all countries in the EU.

Another deterrent from using personal emails is that when people are checking their private email, they are less likely to be in work mood, which can be for or against you. It can be for you due to them having lowered barriers which means they are more likely to open the email. However, it can be detrimental because their mind is not focused on work which means they might not even want to open your email and think about work.

And so, it comes down to one type of email: the corporate email.

Direct corporate emails are the way to go

Here at hubsell we always recommend our customers to target the corporate email of their recipient because it is the most productive of the three options and doesn’t come with the issues related to other two types of emails explained above.

Some time ago I wrote an article on the kind of emails that end up in spam which I highly recommend reading in addition to the content in this article. In the current section ‘subject line’ and the next one ‘message copy’, I would like to tackle some of the key differentiators in ongoing basis after you’ve taken care of the data and technical set-up.

Let’s say that you did everything well. You’ve got excellent data, with only corporate direct email addresses, you’ve set-up your DMARC, DKIM/SPF properly, you’re using your own primary email do the outreach. All boxes checked with stellar ratings. You can mess it all up if you use bad subject lines (like shown in the blog post about email that end up in the spam folder).

Your goal with subject lines

Your ultimate goal when writing a subject line is to get the target to open the email, however with one caveat ‘do not trick or bait the recipient into opening your email’. If you use click-bait tactics to increase your open rate then you’re ‘inflating’ it without an increase in the value of those opens. If you remember at the start of the article I mentioned open to positive reply rate, this metric will decrease if you use click-bait tactics and your unsubscribe/spam reporting rate will go up.

A good subject line has to entice/welcome/encourage the recipient to open your email instead of other emails in their mailbox.

What to do and what not to do

Let’s get into the nitty-gritty.

There is a lot you can do with subject lines as long you remember the following:
• Keeping the number of characters around 60 because most email clients will display between 40-70 characters on desktop and tables, and around 30-60 on smart phone screens
• The character limit in email subject line includes the first n count of characters in the body of the email, i.e. if I have a subject of only 10 characters, then the first 30-60 characters of your email body will be visible in the preview snippet
• In mobile phones (landscape or portrait view) the subject and body are on two separate rows so the length of the subject does not impact how much of the email body is visible to your recipient
• Don’t use CAPS, exclamation marks ‘!’, or more than one question marks ‘?’ (one is okay)
• Avoid spam words and phrases such as ‘free’, ‘money’, ‘risk free’, ‘apply now’ etc (the list is huge – and often times contextual)
• Don’t use numbers or symbols e.g. #1
• Don’t “FWD:” a prefix attempting to appear as if the email came from someone the recipient knows (check my comment on click-baiting)

Some things that I’m on the fence about, I don’t use them myself but some of our customers do and they get results, and some others don’t get results.

• ellipses ‘…’,
• Starting every word with a capital letter
• Generic short subject lines such as ‘quick question’, ‘question’, ‘feedback’ etc.

How to go about writing a good subject line

There are few mental checkboxes you can mark when creating subject lines.

Number one is to ask yourself ‘does my subject line indicate what the email content is about and does it indicate that consistently.’ If it doesn’t you run the risk of misleading or creating clickbait subject line. Sounds simple, it really is not. It’s really hard to take what you said in about a 100 words and summarize it into 10 or so.

Number two is to check the length of your subject line, if it’s 10-20 characters then you need to take the first 20-50 characters of your email body as part of your subject line. Where if the subject line is long you’ll have less room to display the start of the message. See the images below for comparison.

email preview snippet on mobile phones

email preview snippet on mobile phones

So what you see is that on desktop, laptop, tablets your email subject and the start of the email body is on the same row, whereas on mobile phones (also landscape) is on two separate rows.

Static vs dynamic subject lines

Number three is figure out whether to make it personally relevant to the end recipient or not. And if yes (which I recommend) how and to what extent. Let me elaborate on that a little, personalization in the email subject line has been commonly limited to ‘static placeholders’ such as {{firstName}}, {{lastName}}, and {{companyName}} etc. However there is another level which we, at hubsell, called ‘dynamic placeholders’ which use ‘if-this-then-that’ logic to enable personalization in a much deeper way.

Consider the following examples of static placeholder fitted subject lines:

• Quick question about {{companyName}}
• {{firstName}}, quick question about {{companyName}}
• {{firstName}}, quick question about {{companyName}} regarding your [your topic]

Most important thing you should remember is that like anything else in cold outreach personalization is key. A lot of marketers and sales developers fail because they limit themselves to static content.

Now consider these examples of dynamic placeholders fitted subject lines:

• {{firstName}}, {{companyId.Name}} // [your name], [your company name] – intro regarding {{#if (eq department ‘General Management’) }}roi{{else if (eq department ‘Business Development’) }}data{{else if (eq department ‘Sales’) }}conversion{{else}}process{{/if}} driven sales

The dynamic placeholder fitted subject line will automatically adjust itself depending on whether the recipient belongs to the department of ‘General Management’, ‘Business Development’, ‘Sales’ or any other department. So it has subject lines within itself.

Here are the four different versions of the dynamic subject line above:
• {{firstName}}, {{companyId.Name}} // [your name], [your company name] – intro regarding roi driven sales
• {{firstName}}, {{companyId.Name}} // [your name], [your company name] – intro regarding data driven sales
• {{firstName}}, {{companyId.Name}} // [your name], [your company name] – intro regarding conversion driven sales
• {{firstName}}, {{companyId.Name}} // [your name], [your company name] – intro regarding process driven sales

I’ve made the key difference bold in the list above and what you see is that the difference is one word. You don’t have to limit yourself to one word when it comes to the dynamic difference however in my opinion the only word that needed changing, depending on the department, was the word indicating the type of sales process: roi, data, conversion or process.

Now that we have done the following correctly: you’ve got good data, your setup is impeccable, and you’ve written subject lines that hit open rate of the upper 80% (have seen enough times to know it’s really possible), now things get serious.

Paraphrasing the words of the evil but entertaining Calvin Candie (Leonardo DiCaprio’s character in Django Unchained):

‘You had your prospect’s curiosity with your subject line, now with your message copy you gain their interest.’

Some basic points to remember when drafting your message content

With bad content you can really ruin (yes, ruin, I am being that negative), your campaign’s potential. So to avoid that let’s list a few basic ideas and considerations:

• your prospect viewing your message is only the continuation of the process not the end by any means because an opened email that was not answered did not deliver the intended result of initiating a dialogue with the recipient
• your message should not deviate from what is indicated in the subject line otherwise it may be perceived as clickbait (if you’ve ever been rick-rolled you know how lame clickbaiting is)
• just like in the subject line avoid words which are associated with spam (I’ll be doing another long form post about message content in which I’ll list the spam words which should be avoided)
• personalize where possible with a focus on crafting content that provides some type of value to the end recipient, e.g. an insight, interest resource, even humor can count as value
• hypothesize what the message will cause and why (the reason I recommend doing that is because you don’t have to be right you just have to have a structured approach to writing your message to lower the randomness that is not measurable)

Purpose of message content

The content in your message can make or break your campaign. Too many sales devs want to progress too fast in the sale cycle. They are not taking the prospect’s needs into consideration. One of the biggest mistakes you can make while doing cold outreach is to try to sell your product in the message. The message is not at all a channel for selling a product or a service, it is in fact the initiation of an early stage dialogue with a potentially interested party.

I’ve received so many emails that try to sell me their product instead of initiating a dialogue and it’s simply too much to ask from the prospect. A sale has so many steps and the bigger the deal size the more complicated it’s going to get (all other things being equal), so when you try to close a deal or even generate a qualified opportunity on basis of cold outreach, then you’re asking the prospect to do all the work. So make it easy for them, ask them what is absolutely necessary to progress the sale (without losing them) and serve them just enough content that they need in order to convert.

Why buyers won’t convert to sale simply because you contacted them

To seasoned sales people and outbound marketers, the title of this paragraph is totally redundant (probably a resounding ‘duh’ is the main thought in your mind right now), however still a lot of marketers attempt to achieve the exact opposite of it.

In this paragraph I’m going to list a few very important and irrefutable reasons why buyers need to speak to a human (salesperson) to close the deal.

• there is a lot of money at stake
• buying decisions impact other people in the company where this impact is stronger at higher ticket size products
• a lot of the contracts are long term so careful thought is given before the buyer commits
• products have become complicated and need to be explained
• buyers are second guessing themselves all the time and often end up making wrong decisions when they have only considered the ‘online presence’ of the vendor and have not spoken to a real person
• and probably a dozen other reasons

In sum, trying to close the deal via outreach is a sub-par tactic in business to business context.

As I mentioned above in a slightly different way, starting a dialogue with an interested prospect is the best use of cold outreach. Your desired result should be somewhere between the stages of marketing qualified and sales qualified. Cold outreach intended results land somewhere between those levels of qualification.

The subject of message copy is so broad and deep that it can have an entire blog (post) dedicated to it. So I’ll tackle that topic on another day, the current post discusses message copy within the scope of getting the email delivered and opened WITHOUT creating a tricked or baited feeling in the recipient’s mind.

Since I wrote about the kind of placeholders you can use in subject line in the static vs dynamic placeholders subject lines, it’s only fair that I do the same for message copy as well.

Static vs dynamic message copy

As I wrote about in the Subject Line section, we use if/else technology to personalize the message for the recipient. Using dynamic placeholders instead of static placeholders allows an increase in the customization with an order of magnitude (10 times).

Consider the following:

• first name
• last name
• company name
• location
• website
• etc

are all examples of static variables which replace the placeholder with the variable that it represents, e.g first name, becomes Karan, company name becomes hubsell, website becomes hubsell.com. It replaces itself with the variable it represents. If you add 10 static variables you change ~10 words in the message content, if you add 1 static variable you change ~1 word.

On the other hand a dynamic variable allows you to change whole phrases or sentences based on ‘if-this-then-that’ logic. E.g. you use ‘department’ as the ‘if-this’ criteria you can automatically show a whole different sentence to people in department a and department b, c, d, e, f to z. Let’s say that you automatically replace a sentence for each department you’re changing ~10-15 words in the copy for every dynamic placeholder that you use.

~1 word to ~10 words replaced placeholder for static and dynamic placeholders respectively represents an increase customization ability of 10 times.

Why dynamic content performs better

Within the context of open rate topic, I argue that dynamic content outperforms static content and here’s why: it’s because dynamic content is perceived as manually written content compared to static content. Where static message x only differs 5% from static message y, dynamically written messages differ 90% from one message to another.

All other things being equal a more differentiated message receives a more favorable rating when it comes to email service providers.

Once you have your data and content in good shape, it is to time execute your campaign. We’ve now moved to the implementation phase. It’s very important to execute correctly because wrongly implementing your outreach can mess up or at the every least diminish your results.

How most people do cold outreach ‘spray and pray’

In a lot of cases, marketers and salespeople plan their email outreach in the following way:
• Make a list of prospects
• Write a subject line and message template
• Send the 100s or 1000s emails all at once

The ‘spray and pray’ strategy is sub-par because many things can go very wrong and hurt you in the future.

The right way of doing cold email outreach

There is no 100% right or wrong way of doing cold emailing, because it all depends on a multitude of factors, ranging from industry, to location, to authority, etc. Every company has its own values and ideas as well, which might add even more variables.

However, there are main guidelines, we believe at hubsell, that most people should follow. But as we know, these rules might only apply to the near future. At the rate of speed that the internet changes we might be rewriting this blog post next year.

The strategy that I usually follow consists of making yourself look like a human sending regular emails to friends and acquaintances. So how does a normal person (not backed by software) send cold emails? The maximum amount of daily emails would be from 25 to 150, which we will talk about in the next topic, but in terms of sending schedule, it usually is non linear, where the time between the first and second email is not the same from the second and third.

At hubsell our idea was to structure our software to make it send emails with different waiting times between each other, which would be exactly what a regular person would do. This means that you have to aim to have random time intervals between n and n+1 emails. This will allow you to have a much higher chance of getting your message in the recipient’s inbox, without getting blacklisted or damaging the health of your domain.

Sending volume

To prevent the email providers from lowering your domain quality aim to send between 25-150 per day per mailbox. As we talked about before, you want to make them believe that you’re not automating your campaigns, so you need to program your software to send emails like a normal person would, without raising any flags.

Even though you can’t send a lot more emails through this process, the fact that you respect the guidelines means that the likelihood of your email getting through and not going to spam is much higher, and consequently your overall conversions go up. As a basic principle at hubsell we favor high conversion from low volume over low conversion from high volume.

How to circumvent this obstacle

Now, you might be thinking: “Is that it? Can I only send 25 to 150 emails per day?”. Yes, we recommend only sending that amount per day per mailbox. So how do you scale cold emailing? If you know that by sending 150 emails you get 15 of them to schedule a meeting, what if you could send 300 or 600 or 1000 with the same results?

The great thing is that this is totally doable. The only thing you have to do is get more mailboxes. Instead of sending emails out of one, you can start adding more to scale the whole process up. If you get 10 different mailboxes sending 150 emails per day, that amounts to 1500 daily emails sent, which means 150 scheduled calls and finally greater revenue.

A good rule of thumb when doing cold emailing campaigns is to send as many daily emails as possible without hurting your conversions or your domain health, and the tactics explained above do just that.

But remember that even though you might be able to send a lot of emails, that doesn’t mean that the recipients email will be of quality. At hubsell we make sure that all prospecting emails are verified so the integrity of the campaign is maintained. There is nothing worse for your domain health than sending a lot of emails just to find out that you have a high percentage of soft or hard bounces. Here is the whole strategy in image form:

Here is one factor of open rate and deliverability that you cannot impact significantly however you can be mindful of it during your planning stage: the target market.

The market that you target will have certain systemic trends and behaviors that differ from other markets. These difference are partially the reason for variance in campaign results across different industries.

Market saturation

There are some markets who are more mature than others. Some tactics that work in one country might not work anymore in another. This is something that I highly recommend to keep in mind, because cold emailing is still one of those tactics.

Some markets are less saturated than others, so companies won’t be used to cold emailing, which increases your open rates and your call schedules. For example, most of the time, a marketing technique is invented in the US, and then people in Europe start applying it to their businesses as well. This means that some countries can be so far behind that the same technique might continue to work for more years, when in the original country it doesn’t work anymore.

The only con in choosing different countries is that you might have to translate the message to other languages, and possibly hire more people that can expand the market to that country. Therefore it’s important to know who you’d like to target with your strategy.

Time difference

Another concept to think about is the time difference between your company and the clients. If you run a corporation in Europe, it might be okay to do business with countries around you, because at most they will have a 1 to 3 hour time difference at most. But if you want to target Asia or the USA for example, it can be quite challenging to find time to speak with those companies.

As long as there is a time overlap between companies it can be fine. However, some business models don’t allow for that kind of flexibility which immediately eliminates certain parts of the world as potential clients.

Country laws

GDPR adherence is also very important to think about. For example: Germany has very tight rules which means that cold emailing is considered illegal. In the UK the rules are more liberal, so companies can get away with a lot more.

Depending on which countries you’d like to target, I believe it’s important to understand the laws that reign and what the boundaries are. The last thing you want is to get in trouble with officials due to you not doing your homework.

Impact on conversion rates

All of these ideas can impact your conversion rates, so I advise you to go over your ideal customer carefully in order to increase your conversation.

Continuing on the example given above, due to the laws, your german conversion rate might be much lower than the one in the UK, because in the former you’d have to first send an invitation through social media before being able to legally send an email to the prospect, which is another barrier to overcome for you, and another resistance point from the side of the prospect. Here is an image to explain the whole process:

“Be human” is a simple phrase but difficult to replicate when it comes to automation of any task let alone sales specific tasks. There are many tools out there that enable automation of certain activities, however there the question is how closely do they resemble human behavior.

There are two types of automation that I am considering here, one is based on artificial intelligence and the other that is like an assembly like where a sales person (like an engineer) ‘programs’ his activities into the machine. I’m a proponent of the latter and by extension so is hubsell.