Facebook is holding an event in San Francisco today, where it is expected to unveil the new service.
Techcrunch reported last week that Facebook’s new webmail product will allow users to access their accounts away from the Facebook site, and will have personal @facebook.com email addresses.
The new service is also likely to contain social capabilities to prioritise personal emails for the user, in a similar way to Gmail’s inbox priority tool.
In October, Yahoo announced it was making its email service 'more social', allowing users to integrate the mail service with Facebook and Twitter accounts, to create a news feed based on updates from friends and followers within their inbox.
Last week, Google banned Facebook from accessing its API (application programmable interface), to prevent users from importing contact information from Gmail to Facebook.
Facebook refused to comment.