Over the past few weeks I’ve seen quite a few ridiculous comments on forums about people wanting particular iMessage email addresses for each iDevice they have. You need to think if that’s how you really want to use iMessage. That’s certainly not what it was designed to solve.

If you’ve been living under a rock, iMessage is one of the new features Apple added to iOS 5 and is essentially free messaging across your Apple devices.

If you take email as an example you don’t ask people to email you on the particular computer you are using do you? Do you really have laptop@example.com, desktop@example.com, homecomputer@example.com, iphone@example.com or ipad@example.com setup on each corresponding device? Imagine if someone wanted to email you, which one would they use? They want to email YOU not your devices. So you have the one email address configured on all the devices so no matter where you are you can see the message. (you also use IMAP, Exchange or ActiveSync to keep all your mailboxes in sync and don’t use POP3 right?)

The same goes for iMessage. If someone is taking the time you message you then they want to message you not guess if you’re using your iPod touch, iPhone, iPad or Mac and send to the corresponding devices address. (after you’ve somehow given them all those addresses and explained which one to send to to get to which device)

You may be wondering what exactly the point of iMessage is, over, say, WhatsApp?
There are a few benefits,

• It’s free and built in – there’s no need to pay to download (and even go through the hassle) of getting yet another app from the App Store, to live on your home screen
• It’s seamless – you don’t really have to worry about if the other party has iMessage or not – there’s not several different contact lists to maintain. It either magically works, or just sends an SMS
• It has the option of fallback to SMS, when there isn’t a data connection
• Custom tones for messages – unlike WhatsApp, you can choose a default one to apply to all messages, or even use custom ones per contact
• It’s cross platform – perhaps not in the way that WhatsApp is (across different OSes – Android, BlackBerry, etc), but exists across iOS and soon OS X – the iPhone, iPad, iPod touch and the Mac
  This is the biggest downside to competitors like WhatsApp – once you’ve logged in on your iPhone – you can’t log in with your same account/number on your Android tablet for example. You can’t even install it on an iPad or iPod touch.
• Conversations sync – you can start a conversation on your Mac at work, continue it on your iPhone, and then finish it off at home while on the couch with the iPad – while retaining everything. If you read a message on one device, it’s in sync on the others. If you send an attachment on one, it appears on all devices.
• Stateless – there’s no worrying about being online or offline, or having to set a status message – messages are replied to at your own pace
• Configurable read receipts (depending on who you talk to, this is a benefit or a downside!) – while this really is a common benefit with WhatsApp, iMessage allows you to toggle read receipts on/off at your convenience.
• Encryption – this is probably the biggest for businesses and the tin foil hat wearing among you. iMessages are encrypted with authentication done via tokens.
  Change your Apple ID password and immediately iMessage will require you to login before continuing. WhatsApp uses XMPP… in plain text. Everything is sent in the clear – contact list, chats, etc
• Full quality attachments – iMessage allows for full quality attachments to be sent, including Photos and Videos. WhatsApp will compress much more than iMessage. You can also send multiple filetypes from Messages on Mac OS X – you can send an MP3 etc via iMessage from a Mac to anyone with an iPhone
• Multiple Receiving Addresses – as touched on below, you can nominate additional addresses to receive at – unlike WhatsApp which requires you to give out your mobile number, you can tell people to iMessage your personal email, your work email, or a completely different email address.

Of course, there are other benefits over SMS that both (and other apps) share

• ‘Free‘ messages. Messages are sent using your data connection (WiFi or 3G) making it much cheaper than your usual SMS (or MMS)
• Not only free domestic messages, but free international messages – no need to pay international SMS/MMS fees if someone on the other side of the world has data access and iMessage or another app
• ‘More Reliable‘ – you’re not totally reliant on the carrier’s network – with messaging using data connection you’re free to use 3G/WiFi etc. However it then relies on your providers network.
• Works everywhere – you can use apps over WiFi where there’s no 3G access, including overseas while roaming
• Delivery receipts – you are notified when messages are delivered (either to the server (WhatsApp) or the device)

Here’s how I use iMessage and you might want to do the same so your friends can get in contact with you and not have to worry about messaging each of your devices to contact you.

I have an iPhone 4S, iPhone 3GS, iPad 2, iMac and MacBook Pro

Sign into iMessage (or Messages for Mac) with your Apple ID (let’s call it myappleid@evansmith.info) on all my devices.

Messages sent to myappleid@evansmith.info will now appear on ALL my devices and when it is read on one the notifications will clear on the other devices.

Now you may not want to give out your Apple ID address to everyone (I don’t) so setup an alternate address or addresses if you want more than one. Tap Settings > Messages > Receive At and add as many addresses as you’d like. In our example let’s add imessage@evansmith.info and evan@evansmith.info. You’ll also see down the bottom of this screen ‘Caller ID’ so let’s look at that while you’re there.

Caller ID is the address that iMessages you initiate on that device will come from. If you set this the same on all devices (such as your email address) all your conversations will be available across all devices, handy if you’re jumping from one device to another. I’ll go ahead and set this as evan@evansmith.info on all my devices.

Now, iMessages sent to your phone number will be sent only to your phone that has the SIM with that number in it. Until Apple has some sort of feature that registers your mobile number against your Apple ID rather than just the phone you can’t do much about this. Just ask your friends that have iMessage to message you at your desired email address! (and keep reminding them!)

So with this setup I can start my conversation on my MacBook Pro at work, continue it on my iPad/iPhone on the way home in the train and continue again on my iMac at home and whoever is on the other end hasn’t realised I’ve changed devices and their messages have been delivered to me and read by me no matter what device I’m using.

Now if you really, really, really need someone to contact you only on a particular device you could add a ‘Receive at’ email address on a particular device. For example on my iPad I could create ipad@evansmith.info and then give that to someone that I want to message me only on my iPad. I don’t have a reason to do that so I won’t.

Obviously you don’t have to use iMessage like this but it certainly seems the most flexible setup if you’ve got a few devices and want the convenience of picking up and continuing a conversation on any device. And is definitely one of the key problems that Apple decided to tackle when they introduced iMessage

Got any questions? iMessage me! I even have a handy iMessage link on my website where you can just tap on your iOS device or click on your Mac to send me a message. (visit here if you’d like to add an iMessage link to your website/blog)

Beau Giles contributed to this post.