Email Deliverability Warning Signs Heading into Holiday Season

September 8, 2022 | 6 minute read
Heather Goff
Strategic Director of Email Deliverability Services, Oracle Digital Experience Agency
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The last thing email marketers want during the critical holiday season is deliverability problems, which is why many dedicate considerable time during the third quarter to getting their sender reputations and inbox placement rates as healthy as they can get them. However, marketers are facing two unique challenges this year that may foreshadow greater than usual deliverability risks during the all-important fourth quarter.

Challenge #1: MPP’s 1-year anniversary

This month marks the 1-year anniversary of the launch of Mail Privacy Protection (MPP) by Apple. MPP impacts deliverability because when it’s enabled—which nearly every Apple Mail user does because of the scary opt-out language—it obscures real opens by flooding email service providers with many times more fake opens.

That’s a major challenge because opens have been the primary way that marketers qualify subscribers as engaged and safe to mail. Typically, a marketer would look back over a period of time, looking for an open or a click as an indication that the subscriber is engaged. Subscriber engagement is a key indicator for senders because it’s a major component of mailbox provider’s spam filtering algorithms.

The issue now is that when marketers look back, they’re not seeing real opens for the 20% to 80% of their subscribers who use Apple Mail apps. To make matters worse, a lookback window of 12 months is the most common timeframe. Having now passed the 1-year anniversary, brands aren’t seeing any real opens for a significant and rapidly growing portion of their subscribers.

To avoid removing these subscribers from their active mailing lists, brands are doing one or more of the following:

  • They’re using auto-opens as if they were real opens, which is dangerous since auto-opens only indicate an email was delivered and since some spam trap operators may be using Apple Mail with MPP enabled to obscure their traps.
  • They’re expanding their lookback windows for opens, so they can include open behavior from before their subscribers enabled MPP. This is a short-term solution at best, since you invite more risk the more you expand your lookback windows.
  • They’re expanding their lookback windows for email clicks, which are unaffected by MPP. While this much less frequent signal wasn’t heavily relied upon pre-MPP, clicks have proven to be a stronger signal of engagement than opens. Among our clients, clicks have proven to be a safe engagement indicator when looking as far back as 24 months, in some cases. 
  • They’re relying more on cross-channel behaviors such as purchases to qualify subscribers as safe to mail, which is technically challenging, especially if you don’t have a customer data platform (CDP) to aggregate and mobilize your data

Only that last one is a long-term solution. And unlike before MPP, when the same engagement rules applied to everyone, brands will have to figure out which omnichannel behaviors to pay attention to and how long of a lookback window to use for each, all depending on how those decisions affect their email deliverability.

Brands’ struggles to adapt to MPP have caused a decline in deliverability since it was implemented last September, according to Validity, which added that inbox placement rates have fallen from a long-time average of about 86%-87% to 82%-83%. They noted that recycled spam trap hits are also up since MPP was introduced, a sign that some marketers are either counting “fake opens” as actual real opens or expanding their lookback windows so much that they’re mailing email addresses that were abandoned, shut down, and then reactivated as spam trap addresses.

Get our most comprehensive advice on Mail Privacy Protection by getting our Definitive Guide to Adapting to MPP via a free, no-form download.

Challenge #2: ‘Tidal wave’ of Spamhaus listings

In June, the largest blocklist operator, Spamhaus, posted warnings about the mailing behavior of dozens and dozens of major brands. In statements in July and August, Spamhaus confirmed that their “detection techniques, rules, and signals” had changed and that their more aggressive enforcement of abusive senders “isn’t going to stop.”

Thankfully, for those brands fortunate enough to only get “informational listings,” this didn’t cause any of those senders’ email to be blocked. However, it’s an increased risk and a warning that a real listing could be imminent which would dramatically impact a mailer’s ability to deliver email to large portions of their audience.

A real blocklisting on Spamhaus’s blocklist would result in 50% to 70% or more of the average sender’s email volume being blocked or bounced. When that happens, the sender’s email service provider generally halts the sender’s sending privileges. And if the listing isn’t removed in short order, ESPs have been known to fire the customer to avoid larger listings that affect a range of IP addresses from an ESP, which then impacts their other customers.

A search of Spamhaus listings in early September found tons of listings of major brands using major ESPs. One email platform had more than 130 customers with informational listings. Thankfully, a much smaller number of Oracle Responsys customers are listed, and we’re working with them individually to get their listings removed before they turn into a blocklisting. 

Our fear is that, since informational listings don’t impose any penalties on a sender, that some will ignore them. That sets some brands up for their listings to become full-fledged blocklistings going into the holiday season, when they’ll be the most devastating.

Don’t ignore these informational listings. Take them seriously and urgently look to have them removed by addressing the root cause of the issue and by working with Spamhaus to identify remediations and then implement them. Often, the remedies are painful—such as re-permissioning recently added subscribers—but they’re not anywhere nearly as painful as a blocklisting.

Learn how to get off a blocklist and stay off.

Are these two challenges related?

The timing of this wave of Spamhaus listing, coming right before the 1-year anniversary of MPP, strikes us as more than a coincidence. And there’s plenty of evidence that marketers are taking greater risks with their audience selection now that they’ve lost visibility into opens for many of their subscribers. For example, Spamhaus specifically called out senders for not managing their inactive subscribers, which MPP makes more difficult.

That said, it’s clear to us that MPP is only a small contributing factor to this spike in Spamhaus listings. At the same time, it’s also clear to us that MPP will make resolving those listings much harder than it has been in the past.

While we still run traditional reengagement campaigns that only look for an open from a disengaged subscriber, these aren’t effective for our clients’ MPP users. For those subscribers, reengagement campaigns have essentially become re-permission campaigns, where a click is required to indicate that they’re still active and want to continue receiving emails.

Because of how much more difficult remediation has become, it’s more critical than ever that marketers be proactive with managing their deliverability, which means monitoring engagement closely and leaning into strong permission practices like double opt-in. It also means taking warnings from Spamhaus and other blocklist operators seriously, even if they aren’t yet impacting your program. The adage an ounce of prevention is worth a pound of cure has never been more true when it comes to email deliverability.


Need help with your email deliverability? Oracle Digital Experience Agency has hundreds of marketing and communication experts ready to help Oracle customers create stronger connections with their customers and employees, even if they’re not using an Oracle platform as the foundation of that experience. Our award-winning specialists can handle everything from email deliverability and strategy to creative and content planning. For example, our full-service email marketing clients generate 24% higher open rates, 30% higher click rates, and 9% lower unsubscribe rates than Oracle Responsys customers who aren’t.

For help overcoming your challenges or seizing your opportunities, talk to your Oracle account manager, visit us online, or email us at

Want to better understand your email marketing risks and opportunities, take advantage of our free Email Marketing Assessment. Our experts will check your deliverability, review your email creative, audit your signup process, do a partial competitive analysis, and more. If interested in this free assessment, reach out to us at

Heather Goff

Strategic Director of Email Deliverability Services, Oracle Digital Experience Agency

Heather Goff brings her tenacious client centric attitude and over 13 years of experience with email deliverability and digital communication strategy to Oracle Digital Experience Agency in the role of Strategic Director of Email Deliverability Services. Heather’s expertise helps drive deliverability success by arming Responsys customers with strategies to increase engagement and reduce spam traps and complaints. Heather is active in the broader Deliverability community as an active member of the Email Sender & Provider Coalition (ESPC) and the International Association of Privacy Professionals (IAPP).

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