iPad Mail not loading png and gif images, jpgs okay

[Makosuke]

Trying to help a friend diagnose a really weird iOS problem. His Mail app is refusing to load remote png and gif images in certain commercial emails, but jpg images in the same email load fine.

I get the same emails, and images load fine for me on all platforms. The jpgs, gifs, and pngs are all hosted at the same domain. The pngs are smaller than the jpgs, so it's not a matter of size. If I forward an email from that company to him, same results. If he forwards an email to me, the images load fine. If I save the problem images from the exact same email, then email them to him embedded in the message, they load fine. Going to the site in Safari (images hosted at same domain) loads fine. If I message him the URL of one of the images extracted from the source, it loads.

This has been going on for some time, though multiple minor OS updates, and affects all mail from that company, so it's not a temporary glitch or something that a reboot might fix.

Load External Images is on; turning it off shows the "Load Images" message, and tapping it also fails to load the images.

So basically, it's not the actual images, it's not the domain, it's not specific to those messages, and I've ruled out every cause I can think of.

Any suggestions of things to try?

 

[BrianBaughn]

To clarify…you're both on iPhones in iOS 14?

It might help if you can post your list of "I've ruled out every cause I can think of."

The first question is: does he have some sort of ad-blocking running? I can't say why it would only affect PNG/GIF but for most of us going through an ad-blocker is kind of like putting your internet traffic through a "mystery black box".

If that's not it…at this point you can't rule out some sort of corrupted system file on his iPhone. If he does a "restore as new", doesn't restore from his backup, and then re-adds his email accounts and the problem goes away…then it probably was a corrupted system file.

If it occurs on both cellular and wifi then you can probably rule out some sort of weird DNS issue.

 

[Makosuke]

Thank you for the reply.

I indeed failed to identify the devices: I'm on an iPhone 12 Pro on most recent iOS (have also tried on 2 different Macs) and my friend is using an iPad Pro 2020 on most recent iPadOS. I don't have mail set up on the iPad I have access to so haven't tested on iPadOS myself, but am assuming iOS Mail is not that different.

By "ruled out every cause I could think of", I had meant the list of things I already tried. Thus:

• Did not mention, but no, no ad blocker or VPN or the like. Pretty much stock iPadOS.
• Images are specific to the user and there's a server-side glitch? No, same result with email forwarded from one person to the other, in both directions.
• Problem is with a particular domain (ISP or DNS problem)? No, all hosted on the same domain, and both domain and images load fine in Safari.
• ISP blocking some stuff? No, they load in Safari.
• Hosting service is blocking requests from his ISP? No, as above, some images from same domain load and they work in Safari.
• Problem with the actual images? No, if I embed the image files in an email sent to him, they display properly in Mail.
• Mail has something wrong with PNG or GIF parser? No, as above, they display if embedded rather than linked.
• Temporary glitch? No, has persisted through multiple minor-version updates and reboots.
• Load External Images off? No, it's on, and also tried toggling it off and back on.

Regarding your other two suggestions:

Wifi only iPad, so can't test on cellular, but since the images will load in Safari an ISP or DNS issue seems extremely unlikely. I could have him manually enter a different DNS server to test that, but since all images are hosted on the same domain it doesn't make sense that only some of them in the same message wouldn't resolve.

A full restore to solve an OS corruption issue is the one thing he hasn't tried, and if there are no other suggestions the only thing left to do. I may walk him through that at some point, but he's not annoyed enough by it (or having any other issues) to be willing to go through the nuclear option yet.