iOS 16 bug crashes your Mail app with a single string of text

It seems that every year or two, a bizarre bug is discovered in iOS that causes an app or the entire system to crash. One that many iPhone owners likely remember is the Telugu bug. By sending one character in a messaging app, you could crash an iPhone. Now, a similar bug is popping up in iOS 16, but this one only impacts the Mail app.

According to 9to5Mac, VPN Tracker developer Equinux discovered the bug while analyzing spam emails in iOS 16. Here’s how the company describes it:

We started seeing iOS mail problems for multiple people on our team: Mail was crashing immediately on launch. It turns out the team had all received the same spam message.

There weren’t any red flags in the content of the message itself, but the “from” field did look unusual. This is what the field normally looks like:

• From: [email protected].

But this is what the field looked like in the email that was affecting the Mail app:

• From: “”@example.com.

Equinux claims that by taking advantage of this bug, “anyone can send any iOS 16 user an email that can lock them out of their inbox.” The team has dubbed the bug “Mailjack,” as it gives bad actors the ability to effectively keep you from checking your email.

Equinux says that the bug affects the Mail app on iOS 16, iOS 16.0.1, and the iOS 16.1 and the iPadOS 16.1 betas. Other email services such as Gmail, Outlook, and Hotmail rewrite inbound emails, so anyone who uses those apps should be safe.

How to fix the Mailjack bug on iOS 16

Thankfully, the fix for the Mailjack bug on iOS 16 is relatively simple, as the team explains:

As soon as you delete the email from your account using another device, different email client or on the web, Mail updates your inbox and stops crashing. Moving the email to a subfolder in an IMAP email account will also fix your inbox, but Mail will crash again if you navigate to that folder.

If you want to see how the bug works, Equinux actually has a tool on its blog that lets you test the crash by entering your email address. The email might end up in your spam folder. Personally, I’m just going to take their word for it.

More iOS 16 coverage: iOS 16.0.2 out now with fix for iPhone 14 Pro camera shake bug