[GiGifs]

Just updated iMac computers to Yosemite and iPhone 6 and 6+ to iOS 8.3. Now we can't attach photos in iMessage to non-iPhone users. Works fine between iPhone devices. Regular text messages to "green bubble" users are fine, but if we attach a photo, get the red ! and error message "Not Delivered" appears. MMS and SMS are turned on for all devices and tried all the online troubleshooting. Nothing works.

Anyone else have the same problem and find a solution?

[Ledsteplin]

What online trouble shooting? Try toggle off iMessage. Then try Reset Network Settings.
Reset Network Settings
Settings>General>Reset>Tap Reset Network Settings. You may need to enter your wifi passcode back in afterwards.
Toggle iMessage back on.

Check with your carrier.

Sent from my ancient but trustworthy iPhone 5. ☮

[Larry Cook1]

Go into settings: messages; and make sure send as SMS is on.

[GiGifs]

Thanks for the reply, Ledsteplin. I did try this first and all the other suggestions listed. Going to call AT&T next, just in case they've messed our plan and it is just a coincidence that the upgrades and plan mess up happened at the same time. After that, I'll call Apple.

[Darran]

Thanks for the reply, Ledsteplin. I did try this first and all the other suggestions listed. Going to call AT&T next, just in case they've messed our plan and it is just a coincidence that the upgrades and plan mess up happened at the same time. After that, I'll call Apple.

Your carrier probably hasn't provisioned the MMS service for your account if they've created a new account or similar on their end. You often find this. Just call and they will activate it. They used to say to send yourself an MMS to activate it so just turn iMessage off and then send a pic to yourself.