If you're an iPhone user, iMessage is great for cutting down on SMS costs from your carrier, but it doesn't always work right away.
If there are no available Wi-Fi networks around to use, iMessage will attempt to send it over your cellular data, but if you're also in a bad service area or if Apple's servers are down, it will either wait to send it until it can, or just send it as an SMS instead.
In cases where you're in a bad service area, sometimes sending the text as a standard SMS to iMessage users is more reliable—depending on your carrier—and will get there in a more timely manner.
When you updated to iOS 7, Apple automatically disabled "Send as SMS" on your device—even if you had it turned on before.
I've verified this on three separate devices so far, each of which had "Send as SMS" turned on before updating.
Simply go to your Settings, scroll down and click on Messaging, and then make sure Send as SMS is turned ON (i.e. shows a green label).
Now, this is only an issue in regards to sending text messages to other iDevice or Mac OS X Mountain Lion users who have iMessage enabled.
If you're sending a text to someone who has iMessage disabled or doesn't have any Apple devices, it will still automatically send as an SMS through your carrier's plan.
If you're sending a text to someone who has iMessage, and iMessage is down temporarily for some reason, sending it as an SMS could be faster, which is important if you need a quick answer on something.
Though, then the recipient would also have to have "Send as SMS" turned to make sure they give you a speedy response.
Some have reported that messages still hang and that they still don't send as SMS right away when iMessage fails, because it seems to take some time before iMessages realizes it can't send it. Eventually, they might not ever get delivered, or sometimes days later.
Then there's some serious problems with Apple's iMessage system. On Monday, September 30th, Apple acknowledged that 10% of users may have experienced delays or slowness when using iMessages, but I believe it's far worse than that and not limited to just one day.
If you're still experience problems, try restarting your device. That has worked for me on occasion, and something I have to do on a regular basis anyway to prevent my GPS from stalling. Some others have reported success with this, but if you haven't...
- Turn off iMessage (Settings -> Messages)
- Reset Networking Settings (Settings -> General -> Reset)
- Enable iMessage (Settings -> Messages)
This will cause your device to forget previously remembered Wi-Fi passwords, so you'll have to make sure to reenter them before trying iMessage again.
As a last resort, you can try restoring from a backup in iTunes.
Apple released a new iOS 7.0.3 update on October 22nd that supposedly fixes issues with delayed or unsent iMessages, so make sure you update to improve iMessage functionality. To update, just head to Settings -> General -> Software Update.
If you have questions, feel free to ask away below, and please report what did or didn't work for you.
There's a lot to learn about the new iOS 7 for iPad, iPhone, and iPod touch, so make sure to visit our iOS 7 tips section to explore all of the new features and hidden tricks. Also make sure to check out the 15 most annoying things, 18 coolest new features, and 18 sneaky privacy-betraying settings in iOS 7 that every iPhone user should know about.