Email Marketing

The building blocks of inboxing

Everything you need to know about inboxing and why it's important

Email volume has grown by 9% in the last year, while unique click rate has dropped by 14%. The higher email volume and lower email engagement have led to a consistent inboxing challenge for most marketers. At the end, it’s simple: the more you send, the smarter you need to be about how, to whom, and from where you send your mailings. A good way to do that is to implement best practices for “optimal inboxing.”

Meet the expert
Ivy Shtereva
Senior Vice President, Marketing

As the SVP of marketing at Data Axle, Ivy is responsible for multichannel strategy and implementation across all applicable direct marketing channels. She is dedicated to improving the quantity and quality of incoming leads through a combination of engaging content, effective communication strategy, and timely follow-up. Ivy is committed to making Data Axle the undisputed leader in the industry when it comes to data quality, enrichment and management, as well as digital acquisition and retention through technology, services and data.


What’s inboxing?

Simply put, inboxing is the rate at which an email makes it to its intended recipient’s inbox. Logically, the lower a campaign’s inboxing rate, the fewer the number of subscribers who see your email and the lower the open, click, and conversion rates.


Why is it important?

To me, inboxing is the most important component of a marketer’s mailing program and here is why. Regardless of how great or, alternatively, not-so-great your email campaign is, every facet of it can *always* be improved through testing – from subject line, pre-header text, and design, to copy, offer type, etc. But none of these improvements can take place without the email actually making it to the recipient’s inbox. Even the most carefully crafted email becomes irrelevant and ineffective if it’s never seen by the subscriber it’s intended to convert into clicker/buyer/social media follower.


How do Internet Service Providers (ISPs) determine the rate at which your emails will inbox?

Different ISPs have different algorithms to determine how well (or poorly) your emails will inbox. Most of these algorithms take into account the following:

  • Clean subscriber data (which essentially means your data contains no spam traps or invalid emails)
  • High subscriber engagement
  • Predictable mailing volume
  • Consistent mailing frequency

ISPs weigh each component of that algorithm differently. For example, AOL puts a lot of emphasis on engagement (calculated with weighted averages of open & click rates) while ISPs like Yahoo! rely more on predictable mailing volume.


How can we control inboxing?

Clean subscriber data is key; in order to ensure your mailing list doesn’t contain any spam traps or invalid accounts (closed down, poorly formatted, or incorrectly spelled email addresses), you need a clean opt-in process, know the origins of the data you mail to, and be cognizant of how it was collected and validated.

The other 3 components that help you achieve optimal inboxing – subscriber engagement, predictable mailing volume, and consistent mailing frequency – depend exclusively on how you execute your mailing program. If you plan on changing your mailing volume and frequency around peak season, you should gradually start increasing them the quarter before so ISPs have enough time to adjust their expectations and allow your campaigns into your subscribers’ inboxes.

To promote high subscriber engagement:

  • Introduce triggered campaigns (welcome series, transactional messaging, feedback requests, etc.). They garner 2.5X the open rate of regular marketing campaigns and twice the unique click rate.
  • Create audience segments based on subscriber tenure and engagement and mail to the ones that are consistently responsive. The rest you can ‘activate’ from dedicated activation or acquisition domains.
  • Create multiple sending domains so you can mail different segments or different types of campaigns off of each one and have proper visibility into how each segment is performing. This also gives you a ‘Plan B’ if a deliverability issue such as a temporary block or a blacklisting occurs at one of your domains.

While deliverability is not the sexiest component of email marketing, it’s arguably the first and most important step to ensuring your mailing program does its job – reach your subscribers, engage them, and eventually, convert them to repeat purchasers.

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