Vivek Sharma has been in charge of Yahoo Mail and Messenger since 2009. After three years of working on the product, Sharma may have decided that it's time to move on.
All Things D is reporting that multiple sources have confirmed that Sharma has left Yahoo. It's unknown at this time why he left the company, or what he intends to do. All these unknowns have led to some rumors gaining traction.
One of the most prevailing rumors is that Sharma's departure was not amicable. It's said that he didn't see eye-to-eye with new Yahoo CEO Marissa Mayer, or her decision to overhaul Yahoo Mail. Other rumors say that he just thought it was time to move on.
Like all rumors, these must be taken with a grain of salt. It has still not been confirmed that Shamar has even left the company, but multiple sources all reporting the same thing seems to indicate that there is at least some truth to the report.
If Shamar has indeed left Yahoo, however, that will mean Mayer has to find a new head for Yahoo's Mail and Messenger products. On top of finding a replacement for Shamar, Mayer also has to find replacements for former Yahoo Connections SVP Shashi Seth and Chief of Information Security Justin Somaini, both of which left in January of this year.