Resources Hub » Blog » What Does iOS 15 Mean for Email Deliverability?

In the fourth post of our Demystifying Deliverability series, we take a look at Apple’s Mail Privacy Protection feature and the effects it has on email deliverability. To catch up on the rest of the series, check out our posts on ramping up your email marketing, bot clicks, and BIMI.

The 2021 email marketing busy season is upon us. Holiday decor is going up, and, just as rapidly, email marketers are sending Black Friday offerings to their subscribers. 

As is normal for this time of the year, global email traffic will increase over the coming weeks. And with that, mailbox providers will be under strain to manage the surge in volume. 

It can be a stressful time for email marketers, and Apple’s Mail Privacy Protection (MPP) has added an extra layer of complexity. Not knowing the full effects of this feature on email deliverability can cause serious concern among email senders.

But fear not for fear is the mind killer! In this article, we will examine the email ecosystem, what’s changed in light of MPP, and the factors that affect your deliverability this holiday season.

A quick overview of the email ecosystem

To win the very competitive inbox game (especially at this time of the year), we need to know the rules of email and the other players in the game.

For simplicity’s sake, we will consider the four main players.

Image showing the four main players in deliverability.

  • The Sender: the individual or organization sending the emails
  • The Email Service Provider (ESP): the service, like Campaign Monitor, used to send emails
  • The Mailbox Providers (MBPs): the service, like Gmail or Yahoo, that provide individuals or organizations with a mailbox to receive their emails
  • The Subscriber: the individual that receives the email

Subscribers hold the power

In October 2021, an average of over 90 billion spam emails were sent every day. It is the MBP’s responsibility to protect its users and reduce the risk of unwanted and unsafe emails landing in the inbox. This is why MBPs use strict anti-spam filters to protect their users.

MBPs rely on their users, and how they interact with an email, to train their anti-spam filters on how to treat future emails from that same sender. In fact, user engagement and sender reputation are the most influential factors for inbox placement.

Image showing the actions a subscriber can take to effect deliverability.

The more subscribers interact and engage with an email — which MBPs call “positive signals” — the more emails from that sender will make it to the inbox. And the less engaged an audience is with emails from a particular sender, the more likely they’ll filter those emails into the spam folder (or block them entirely).

These positive and negative signals help make up your domain’s sender reputation. And a domain can have different reputations at different MBPs, too. Meaning, Gmail might score things somewhat differently than Yahoo, so your domain can have a slightly different sender reputation for each. It’s less of a single, universal score, and more of a combination of many factors.

That said, since engagement is the most weighted factor for deliverability, it’s essential for marketers to put user engagement and subscriber experience at the front and center of their marketing strategies.

It’s also important—particularly in this season of heavy sending—to monitor your delivery and engagement metrics for each MBP regularly. This way, you’ll know if you’re having issues reaching any particular inboxes.

How does iOS 15 affect email deliverability?

In September 2021, Apple released iOS 15 to the public, and with it, a new privacy feature called Mail Privacy Protection.

We’ve gone deep into detail on MPP here, but the quick summary of the feature is this:

MPP obscures senders’ ability to track open rates, meaning the future of open rates, and the use of this metric to measure success, is changing in real-time.

This feature caused a huge stir in the email world (and understandably so!). Since its announcement earlier in the summer, marketers have been preparing for MPP and its effects on email.

That said, we’re still learning how deeply the effects of this feature are going to play out. Though iOS 15 has been available for a couple of months now, adoption is still relatively low. 

That being the case, it’s difficult to predict what impact, if any, MPP will have on this holiday season. Even if adoption was higher, it’s important to remember that, just because a user opts into MPP, doesn’t mean MBPs will treat incoming emails differently. In a real sense, deliverability has not changed with the release of Apple’s Mail Privacy Protection.

What it does mean, though, is that you’ll have to change the way you view engagement when monitoring your delivery and engagement metrics.

MBPs still use the same signals to determine how to filter incoming emails. And senders still need to comply with email rules and follow best practices. To stay on top of your deliverability this holiday season, make sure you do the following:

  1. Get clear opt-in when collecting your list. Sending to a fully opted-in list means higher engagement. Which, in turn, shows more positive user activity to the MBP.
  2. Manage and segment your lists. Sending to active subscribers means more engagement and more inbox placement. Sending to an old and unused list means lower open rates, higher bounce rates, and more spam complaints—all of which are negative signals to the MBP.
  3. Focus on list hygiene. Permission to send emails isn’t evergreen, and monitoring list hygiene is an ongoing process. If a subset of a list has poor engagement metrics, consider trying to re-engage that particular group. And if that doesn’t work, feel free to say goodbye to the dormant contacts altogether. 

Wrap up

Senders still have time to review their marketing programs and prepare for the holiday season. Even if your holiday programs have already begun, it’s still not too late to follow these deliverability best practices.

Be sure to check out our Ultimate Guide to Holiday Email Marketing in 2021 as well. It’s full of useful tips for marketers who will be ramping up their email output for the next couple of months.

And, as always, make sure to engage with your audience with honesty, respect, and clear communication. Do those things, and you’ll make it through this season just fine.

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About the Author John Peters
This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
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