Download this article as a PDF document


Related Resources

Overcoming Email Deliverability Challenges

The email marketing landscape has seen a lot of change in the last few years. The emergence of mobile, new apps, contextual marketing, consumer demand for personalization, new legislation, and so on, creates an ever-growing list of priorities for email marketers. Through it all, one area remains the bedrock of successful programs – deliverability. Ensuring continual inboxing to your subscribers leads to higher opens, conversions, and revenue. Unfortunately, deliverability also happens to be one of the least understood areas in the email lexicon.

To help shed some light on the situation, we’ve highlighted the top deliverability challenges facing email marketers today, recommended steps to mitigate them, and provided five essentials to incorporate into your program now for long-term inboxing success.

Top Challenges:

Understanding the difference between ‘Delivered’ and ‘Inboxed’
One of the most misleading metrics in email marketing is ‘delivered’. The long-standing KPI of deliverability, ‘delivered’ is calculated by subtracting the number of bounces (hard and soft) from the volume sent. While this metric is valuable, it is also deceptive, as it provides no insight into the number of ‘delivered’ messages that actually reached your intended customers. It does not differentiate between the volume of messages that landed in the subscribers’ inbox versus their junk folder (or that went missing entirely). While having a high ‘delivered’ rate is important, savvy email marketers also focus on how well their emails are inboxing at the various ISPs to ensure that they can be opened, read, and clicked, to drive conversions and revenue. Using a service like Return Path will help you monitor inbox performance.

User Engagement and Inbox Filtering
With more ISPs like Yahoo! and Gmail incorporating user-engagement into their inboxing algorithms, email marketers need to keep a closer eye on open and click performance trends. The best place to start is with your segmentation bands. Create segments for new, active, and inactive subscribers, and monitor engagement by ISP, campaign, and time. Focus your efforts on the ISPs that account for the majority of your email database like Gmail, Yahoo!, and Hotmail, and keep an eye out for declining performance. Adjust your sending strategy when declines occur to keep your engagement rates high and ward off inbox filtering. Develop a re-engagement strategy to handle inactive subscribers who have not engaged in a long time. Removing them from your regular messages will go a long way toward preventing declining performance.

IP Blocks and Content Fingerprinting
The most impactful deliverability issue is IP blocks. Most ISPs maintain a blacklist of IP addresses and IP ranges for senders who have received too many customer complaints and appear to be spammers. There are also private block lists and content filters, like Postini and Barracuda, who filter email for private domains. IP blocks incur the largest damage as no mail is delivered to that ISP until the block is resolved. Proactively monitoring performance – sending frequency, user engagement, opt-out, and complaint rates – is the best way to prevent blocks from occurring. Be sure to continually optimize your sending strategy based on these trends. When a block does occur, review your bounce logs to determine root cause and modify your sending practices by deploying to only your most engaged users at that domain.

And be sure to refresh your content (image sources and HREF URLs) to prevent fingerprinting from retriggering blocks. Fingerprinting is conducted most commonly by the Cloudmark domains, whereby content from a message that previously incurred a block is flagged and can retrigger a block if seen again. To remove an IP block, contact your BlueHornet Account Manager. Our Deliverability Specialists monitor for IP blocks daily and work with the ISPs to have them removed in a timely fashion.

Temporary Timeouts, Data Validity, and Throttling
The last major deliverability challenge is also the most common – temporary timeouts. Whenever a negative threshold is crossed at an ISP – e.g., too many invalid addresses received, too many hard bounces or complaints occur, or in some cases, simply too much volume is sent in a short time – an ISP can temporarily decline receiving mail. Temporary timeouts normally last 24-48 hours and resolve themselves. They occur most frequently at Yahoo! and AOL. The best way to prevent timeouts is to ensure that you’re sending to an engaged audience of organic subscribers. You can also use an email validation service to weed out invalid addresses from your database if you’re sending to older and unengaged subscribers or have some less-reliable acquisition sources. Lastly, a good counter-measure is throttling, whereby you limit the volume of messages sent at one time. This tactic delivers great results in preventing temporary timeouts because by reducing the number of emails sent at one time, you also (by default) reduce the likelihood of crossing an ISPs negative threshold of invalids, bounces, volume, etc.

5 Tips to Improve Inboxing:

Now that you have a better understanding of the top inboxing challenges, we’ll leave you with five tips for optimizing your program right away.

  1. Monitor your IP Reputation: Maintaining a positive IP reputation is essential to successful deliverability. Leverage our new Return Path services to monitor performance.
  2. Focus on Organic Acquisitions: Even though its cliché, quality still trumps quantity. Build your email database through responsible and organic means.
  3. Prioritize your Welcome Series: The post-subscription period is a highly engaged time so use it to lay the groundwork for long term success. Read more here.
  4. Leverage your Preference Center: Give your subscribers the opportunity to opt-down or adjust their messaging cadence. Receiving less is not a bad thing – it will likely increase the number of messages they actually engage with.
  5. Ensure Content Relevancy through Personalization: Content is still king, so be sure that you’re delivering content tailored to your subscribers as best you can.
Return to Resources Page >