Facebook has ramped up competition with AOL, Yahoo, Microsoft and Google with a product to rival their email services.
BBC News Technology writer Maggie Shiels reports Facebook Messages aims to tie users more closely to the social networking site at a time when everyone is battling for their attention.
The product will merge texts, online chats, and emails into one central hub.
Facebook said traditional email is too slow and cumbersome and needs to step into the modern world of messaging.
"This is not an email killer," Facebook co-founder Mark Zuckerberg told reporters and analysts at an event in San Francisco.
"Maybe we can help push the way people do messaging more towards this simple, real time, immediate personal experience. Email is still really important to a lot of people. We think this simple messaging is how people will shift their communication," added Mr Zuckerberg.
At the heart of Facebook Messages is an effort to ensure users "see the messages that matter".
The new feature will simplify how people communicate whether it be via text, instant messages, online chat or email. All these messages will come into one feed known as a social inbox allowing users to reply in any way they want.
Other features include being able to store conversations so users can have a complete archive of communications with friends and family. Mr Bosworth likened this to a modern day treasure trove of letters stored in a box.
Incoming message will be placed in one of three folders - one for friends, another for things like bank statements and a junk folder for messages people do not want to see.
The product will also represent a challenge to Yahoo with over 273 million users and Microsoft which has nearly 362 million.
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