Maxmail HQ Email Marketing Blog

Understanding Email Delivery Rates

Confused by all the jargon thrown around when people talk about how to get emails delivered successfully?

Here is a non-technical explanation of the main words and concepts. (Email technologists may want to look away.)
Email deliverability

The numbers of emails you send out does not equal the number of emails that arrive at their intended destination (the recipient’s inbox.) This article explains why.

This fact leads us to talk about email deliverability, which is a term with two meanings…

1. It refers to the whole subject area of getting your emails delivered to the right place.
2. It refers to your concrete success at getting your emails delivered to the right place.

So when someone mentions a deliverability issue, they are talking about something affecting the delivery of their emails. When they ask “How do I improve my email deliverability?” then they are simply asking how they can get more emails successfully delivered to recipients.

All the rest of the terms in this mini-glossary are, therefore, deliverability jargon.

Some general concepts

Various organizations are involved in delivering email. Yahoo, for example, manages the incoming email for over 250,000 email accounts at their Yahoo! Mail service. Large corporations manage the incoming email to their employees’ email accounts.

One of the main tasks for these organizations is deciding which emails to deliver to their email users. In a perfect world, this would be easy. They’d just deliver all of them.

But in a world of spam, these organizations (or rather the technology they use) have to make a judgment call on each email. At a basic level, it looks like this:

* Do we delete this email and not deliver it to the email account?
* Do we deliver the email to the account, but mark it as spam or perhaps send it straight to the junk folder in the user’s email interface?
* Do we deliver the email straight to the inbox?

Often, there’s another layer of management at the receiving end. If you use desktop email software, it also makes a judgment call on incoming email. So your company may deliver the email to your desktop inbox, but your email software might divert it straight to the delete or junk folder.

Most of the terms used in deliverability refer to procedures or technologies which help organizations and software make the right judgment call about incoming email. Procedures and technologies that help them accurately label email as spam/unwanted or legitimate email/wanted.

Spam filters and anti-spam technologies

Anti-spam technologies are any mechanism in place to identify spam and deal with it accordingly. There are hundreds of different technologies operating at various points in the chain of events that leads to the delivery of an email to a user’s inbox.

People often talk about spam filters or email getting filtered. A spam filter is a broad term used to describe any technology or process where an incoming email is examined and then tagged as a legitimate email or as spam.

If it gets tagged as spam, then it gets “filtered out,” meaning deleted or routed to a junk folder rather than the recipient’s main inbox.

There are many types of spam filters using different criteria to decide if an email is spam or not. But we can split these criteria into two broad groups.

One set involves the content of the actual email itself. What words are used in the subject line and main body text?

So, for example, if a subject line is “PENIS ENLARGERS FOR U!!!!!”, then chances are a spam filter would put a tick against that email on their spam checklist. Get enough ticks, and the email is filtered out.

Another set of criteria concerns the route the email has traveled. Who sent the email? Where did it come from? Where does it suggest people go to (links)?

So, for example, if the email originated from somewhere known to be a regular source of spam, then that’s a tick on the spam checklist.
Spam reports

Spam reports are where the receiver of a particular email decides it’s spam and reports it as such. The nature of these reports has important implications for deliverability.

Case 1: User reports spam to the organization managing their account

If you use a webmail service like Yahoo! Mail or Gmail, then you have a “report as spam” button or similar on the screen whenever you view your emails.

Using that button sends an automated report to that service about the email you’re viewing. The service then uses these reports to refine their anti-spam technologies.

For example, if enough people report email sent by “Acme Engineering” as spam, then the service might decide to block all future emails from Acme Engineering from reaching their users.

Case 2: User reports spam to a third-party anti-spam organization

Many people make a point of reporting what they see as spam to one or more organizations actively working to combat spam. As with Case 1, these organizations use the spam reports to identify spammers.

Those so identified get added to “bad sender lists” (see “blacklists” below) which are made available to organizations managing incoming email so they can reject email coming from a source on that list.

Case 3: Users report spam to the email software they’re using

Email software also has “mark as junk” or “spam” buttons which users can activate when they see spam in their inbox. The software typically uses these spam reports to refine its own spam filters. So future emails sharing similar characteristics to those marked as spam get tagged as spam, or diverted on arrival to junk/delete folders.
Blacklists

Blacklists take various forms, but are essentially a reference list of “naughty senders” that anti-spam technologies can draw on to quickly decide if an email is spam or not.

An organization might have a unique proprietary blacklist of bad email senders built through its own experience with incoming email. Or it uses one of the publicly-available lists provided by third-party anti-spam organizations.

When email arrives at an organization, the anti-spam technologies check the sender against the blacklist (or lists!) they’re using. If the sender is on a list, it’s tagged as spam.

That’s the simple version. There are lots of nuances to the different blacklists out there and how they are used.

Whitelists

Whitelists are the natural pendant to blacklists. These are lists of “good senders.” Getting on a whitelist allows your email to automatically bypass one or more of the spam checks and filters an organization might use.

Unfortunately, there are no global whitelists out there that allow your email priority delivery to any email account. Many (but not all) of the big email services run their own whitelists, and the process involved to get “whitelisted” differs from list to list.

As with blacklists, there are also third-party organizations that run whitelists which others can use.

The terms whitelist and whitelisting also refer to individuals giving your email priority access at the level of their own email software.

For example, you may see experts recommend that the welcome message you send to new subscribers should include instructions on how to whitelist you.

This means you should tell people to add your email address to their private whitelist or (usually) their email address book. Now when you send emails to that recipient, their email software recognizes you and is likely to treat you as spam.

As well as helping with the delivery of your email, whitelisting may have other side benefits.

Some email services and software, for example, prevent images in emails from displaying. If you are whitelisted with that service or software, then your images might show up while those of your not-whitelisted competitor won’t.

Email certification

Email certification is where an independent, third-party organization declares that your email practices conform to some kind of desired standard. Normally a certification fee is charged, after which the certifying body conducts an audit of your practices. You could also use enterprise level email marketing solutions like Maxmail HQ which already has extremely high deliverability rate to bypass the need for one-to-one certification.

Certification takes various guises, involving one or more of the following concepts:

1. If you pass the audit, you are added to the certification agency’s whitelist. Email address services recognizing that certification may use that whitelist and give your emails priority treatment (as described above.)

2. Email certification is also used to refer to programs where complying with a set of criteria allows you to display some kind of certification seal on your website. This is similar to the privacy seals you often encounter on retail websites.

3. A more recent development is certification that puts a “certified” icon next to your email, indicating to recipients that your email is both authentic and complies with the certifying agency’s email standards.

Email authentication

The success of efforts to clean up the email world hinge on the ability of those managing incoming email to properly identify the sender of each email.

Email authentication refers to new standards used to accurately identify email senders. When a sender “authenticates” their email, it means they follow the requirements of these standards so that organizations receiving their emails can say with certainty where they originated from.

Increasingly, authenticated email is considered a big plus by anti-spam technologies.

Email sender reputation

Email (sender) reputation is a broad term used to describe your standing with those organizations managing incoming email to end-user accounts. As anti-spam technologies evolve, so they are relying more and more on this holistic concept of reputation to determine whether or not your emails should get delivered.

The better your reputation, the more likely you are to pass all the spam checks and filters. Which begs the question, just what makes a good reputation?

There are various criteria that contribute to a good sender reputation. The main ones are:

1. You don’t send messages to email addresses that no longer function.
2. Your emails don’t generate spam reports.
3. The links you use in your emails are not associated with any bad emailers.

Some would also say email authentication enhances your reputation. Others treat authentication as a separate issue.

Of course, “don’t get reported as spam” is a fairly glib answer to how to increase your sender reputation. In essence, what sender reputation really means is that your whole email program should follow established best practices in terms of list hygiene, permission, relevancy, subscriber management etc. etc.

Learn more about reputation

Understanding the terms used in email deliverability is one thing. Applying that knowledge to get more emails delivered is another. Explore the articles and links on this topic to learn how to do exactly that. Good luck!