Back in November 2010, Facebook announced plans for a 'social inbox' – a place that would serve as a hub for all communications that people use online or via mobile phones, ranging from text messages and chat messages to email messages, too.

This week Facebook began releasing Messages to more users and will continue to do so over the next few months. CEO Mark Zuckerberg said he intends Messages to make communications more "seamless, informal, immediate, personal, simple, minimal and short".

Subscribing to Messages might not be for everyone - after its announcement, Facebook users expressed skepticism over its promise to simplify communications and cited Facebook's flawed privacy track record. Experts, however, say that while the adoption of Facebook's take on unified communications will be slow, it is a growing trend.

Here's a detailed look at Messages and its features for when you gain access, and a few cautions before you sign up.

Before you start

When you sign up for the new Facebook Messages, you're assigned a Facebook email address. All messages sent to this address will appear in your Facebook Messages inbox. How you use this email address and inbox is up to you - for some, it may become your primary account where you receive retail offers, emails from friends and family or even bank statements. But for others, it will probably become a convenient way of keeping all communications with Facebook friends - whether it's a message, chat, email or text message - in one spot.

It's important to note that anyone who knows your address can send an e-mail to that account, whether or not they're a Facebook user. When someone sends you an email from external systems, such as Gmail or Hotmail, they're formatted to look like your messages on Facebook, complete with your name and profile picture.

Also, consider this: many Facebook users have probably checked out a handful of apps, whether they're games, photo-altering apps or business-focused apps. When you use these, you grant the applications permission to access certain information and message you. That means these applications will now be able to message you via your Facebook email address.

Finally, note that once you set up a Facebook email address, it will always be valid - you cannot deactivate it. You can, however, change its privacy settings. The strictest setting allows only your Facebook friends to contact you via the email address, all other e-mails will receive bounce-back replies.

NEXT PAGE: Getting started

  1. Take a tour round Facebook's 'social inbox'
  2. Getting started
  3. Navigate the interface
  4. Turning on text messaging