Yeah, I know. Apple blew up open tracking. Other things have been gnawing away at it for a while, but where we're at now is that for anybody who reads their email messages on a modern iPhone, whether or not they opened the message is no longer something an email sending platform can track accurately. Sparkpost points out that we're basically at the saturation point: 45-55% of all opens are now now via Apple MPP-enabled users (and thus cannot be trusted).
But you know what Apple didn't break? Your ability to identify (most) of the unengaged. If you're looking to segment out your unengaged subscribers, those who haven't opened or clicked in months, proceed as you would have prior to MPP. There's a margin of error that wasn't there before -- you won't catch all of the unengaged -- but truly, people who show as never having registered? They're still very likely inactive. No click, no open, no ticket, no biscuit. Suppress them or segment them. Stop mailing or segment them out and adjust the cadence and strategy -- whatever you do, getting them out of the normal course of your everyday email program is still going to help boost engagement (and thus boost your sending reputation, improving your inbox chances) at your bigger consumer webmail providers like Gmail.
So don't write off open tracking just yet. Do recognize its limitations, and yes, you should run screaming from the people who tell you they can defeat what Apple's doing (they're full of beans), but remember that there's still useful deliverability data to be had there.
