I've been getting a lot of questions from all channels (LiveChat, SMS, What'sApp, iMessage) about iMessage so here's a short FAQ on it
What is iMessage?
In my laziness, I decided to quote excerpts from an article by
Glenn Fleishman
Apple has pulled the neat trick in this release of providing you a tool, called iMessage, that lets you bypass any service fees associated with text messaging (SMS) and multimedia messaging (MMS) that you pay for separately as part of a mobile plan. iMessage is available without any extra configuration in the Messages app.
Messages bypass carriers' systems whenever you communicate in the app with another iOS 5 user, whether on an iPhone or an iPod touch or iPad. For iPhones, your phone number is registered in the system, while an email associated with an Apple ID is connected for all iOS hardware. You can later add other email addresses.
Start a message to someone whose phone number or email address is registered in iOS 5, and Message switches the color of the text balloons from green to blue, and displays "iMessage" in grayed-out type in the field in which you tap in text.
IMessage works across carriers and international borders, and is free. When a message is received, Messages shows the word "Delivered" in small type under the corresponding blue balloon. An iOS 5 user can configure Messages to also show when a message is read, but you may find you're giving away too much information to the sender. (Apple turns that option off by default.)
Facts:
1. iMessage is cool!!! It is the new messaging system by Apple for iDevices.
2. iMessage requires data connectivity, whether it be via cellular/mobile network or wi-fi. B
3. iMessage doesn't require an iCloud account on the initial setup. You can start using iMessage OTB provided you comply with Fact #2. By default, iMessage is turned ON.
Try sending an iMessage to yourself first before anything else to verify your iMessage works.
The only time your iCloud account comes in to play is if and when you want to receive messages at your iCloud managed email addresses.
If you want both devices to receive the same iMessage, set both to receive at that one address. Next question I foresee you asking,
"If I put my email on the Receive at section to match the iPad2 and the Caller ID, how will people be able to text me if they don't know that email?"
Answer: (for the iPhone) for as long as people know your cellphone number, they will still be able to send and receive iMessages to/from you since, for the iPhone, the phone number is automatically assigned as the iMessage ID as well For messages sent directly using your phone number, they will not show up on your iPad.. Your responses, however, will, since your are sending via your Caller ID
Again, the key here is to use the same iCloud account for both devices and email addresses must be one that is managed and verfied by your iCloud/Apple ID. You need to go to appleid.apple.com and assign all the email addresses that you would like tied in to your AppleID and verify it (appleid send out a verification for each email you assign) Once that is done, your can assign them at the Receive at section.
4. iMessage does not get charged the same way SMS is per message sent. Why? Because it does not go thru the carrier network's SMS messaging system. It uses the internet to send/receive messages (think Yahoo Messenger, Windows Live Messenger, etc)
5. iMessage servers do store your messages. If your recipient is offline, iMessages are stored on Apple servers until such time that the recipient goes online again. This occurs if you are sending the iMessage to an email message id, or sending the iMessage iphone-to-iphone and you have set "Send as SMS" option to OFF.
The "Send as SMS" is only application when sending messages between iPhones.
If the "Send as SMS" option is ON, iOS5 will, upon detecting that your recipient is not online, send the message via the carrier's SMS system, and you get charged SMS rates.
The Send as SMS option is both boon and bane and is something that you will need to be conscientious about. What this option does is allow you the flexibility of being able to make use of both message transport worlds (your carrier's and Apple's), if and when to use it.
If you have tons of international contacts, who are also on iOS5, and you frequently send them messages, my advice is to set "Send as SMS" option to OFF to avoid international texting charges
The Send as SMS option does in no way affect your regular SMS capabilities if iMessage is turned OFF.
Yes, iMessage can also send photos, pretty much like an MMS, but without the carrier charges
6. iMessage can send from one caller ID, but receive messages at multiple IDs. By default, your cellphone number is the default ID iMessage will use as the Caller ID and it is the ID that identifies you to your friends
For iPod Touches and iPads, it is your AppleID or other email address associated with your AppleID (more on that in a bit)
On the Receive At section, make sure the email address you enter there is one that is managed and validate thru your iCloud/AppleID account.
How you want people to see where your iMessage is being sent from by setting the Caller ID. That setting can be found in Settings->Messages->Receive at->Caller ID
7. iMessage knows if your recipient's device is on iOS5 and if connected to the net, will automatically shift message sending via iMessage.
-- Blue message bubbles means your ongoing text conversation is being done thru iMessage.
-- Green bubbles tell you that you are using the providers SMS messaging system.
8. iMessage is a feature of the default Messages app. It is
not a standalone app like BiteSMS and therefore cannot be set as the "default" messaging transport or "app". How an iMessage gets sent is determined by three factors:
a. The recipient's device is on iOS5
b. iMessage is turned ON and using a validated AppleID
c. The recipient's device is connected to the internet
9. Turning OFF iMessage does not affect your normal SMS functionality.
Tip: If for some reason your phone can't seem to get registered properly, try to clear out your iCloud ID and email addresses at the Receive at section do a Reset All Settings
Note for carrier-locked unit owners who rely on ultrasn0w or interposers, who have "accidentally" jumped the gun on the update:
While you may use other methods to hacktivate your units, e.g. thru SAM, for some reason, you can activate using an iCloud-managed email address but you will not be able to register your non-officlal cellphone numbers to the iMessage servers as the caller ID.. This is because your local carrier number is being seen as invalid, therefore cannot hook onto the official carrier's network
iMessage treats your phone now as just an iPod Touch/iPad and you will only be able to use your email as the caller ID and as such, can only receive iMessage at that address
Update #1 as of 10/22: Thanks to
MFB's question, it seems that iMessage activation is tied to Facetime activation as well. I did a simulation of restricting Facetime and not only did it turn OFF iMessage, but it does seem to stay stuck at Verifying your phone number as well when you turn it ON.. Email addresses seem to work fine though.. Researching further on this. Again, thanks MFB for bringing it to our attention
Update #2 as of 10/23: Thanks to
benzng of Philmug for the possible solution to Update #1 and Kingplopi for finding and sharing his post!!
Please feel free to post your questions and we will try our best to answer them and update this first post. Let's help build the FAQ for iMessage
PS.. this is not yet complete.. i am getting too old for multi tasking
work in progress.. screenies to follow...
Forums 
