TS2755 Sending pictures via iMessage - "undelivered"

Question

Hi,
having iPhone 5 with iOS 7 (the newest one) and having problem with sending pictures via iMessage. The picture is usually sent and marked as "delivered" but after few seconds it´s showed again as "undelivered" with red exclamation mark. I have tried to reinstall the iOS, I changed the phone at all (like to different piece of device) and the problem is still there.
This is happening as well when someone is sending pictures to me - shows them the exclamation mark as well despite the picture is usually already delivered.
Many thanks for your opinions what can I do...
BR
Martina

Answer 1

Hello there, Martinacep.
It seems you were referred to us from the very article that provides some troubleshooting recommendations for issues with sending attachments via MMS:
iOS: Troubleshooting Messages
http://support.apple.com/kb/TS2755
To begin, follow these initial steps:
If you can't send and receive MMS
You will need these to send and receive MMS:
An iPhone 3G or later
iOS 3.1 or later
A cellular data connection (MMS isn't available if you're using only Wi-Fi)
A domestic MMS plan from your cellular provider. You might need an international messaging plan to send MMS to an international contact (Contact your carrier for more information.)
A roaming MMS when using a cellular provider's network that is different from your billing cellular provider's network (Learn more about roaming and contact your carrier for more information.)
To resolve issues with sending and receiving MMS, follow these steps
Go to Settings and turn airplane mode off.
Go to Settings > Messages and turn MMS Messaging on.
Go to Settings > Cellular and turn Cellular Data on.
Go to Settings > Cellular and turn Data Roaming on if you're roaming on a cellular provider network that is different from your billing provider's network.
Make sure that you have a cellular data connection in the status bar of your iPhone.
Go to Settings and turn Wi-Fi off. Open Safari and navigate to www.apple.com to verify that you have a data connection. Turn Wi-Fi back on to continue using Wi-Fi for other features. If your cellular data connection isn't available, follow these steps.
Make sure that you can send and receive SMS. If you can't send and receive SMS, see the "Issues with sending and receiving SMS" section, above. MMS might not be available while you're on a call. Only 3G and faster GSM networks support simultaneous data and voice calls. Learn more about which network your phone supports.
Restart your iPhone.
Tap Settings > General > Reset > Reset Network Settings on your iPhone.
Remove your SIM card and insert it again.
If the issue persists, then follow the section entitled "If you still can't send or receive MMS, follow these steps" that follows the one above in the article.
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.