Mail.Ru Agent (MRA, M-Agent) is a free instant messaging program created by Mail.ru, one of the largest Russian web portals. Besides basic IM functionality (presence, contact list, sending text messages, file transfers, message history, etc.), M-Agent also provides online gaming, peer-to-peer voice calls, video calls, low-rate VoIP calls, free SMS, automatic mail checking and other useful features.Mail.Ru Agent runs under Microsoft Windows and communicates with server using proprietary (but partially documented) protocol called MMP that works over TCP/IP. Mail.Ru Agent uses portal e-mail address as unique user ID.