The back of an envelope, shown coming into an inbox or arriving with motion lines.
Commonly used as an icon for an email address. May also represent posting mail or sending messages more generally.
Apple and WhatsApp’s designs include an inbox tray. Microsoft and Facebook’s designs feature a yellow envelope angled forward and trailed by three, blue lines, indicating sending.
Apple’s design previously featured three red motion lines, Microsoft’s a right arrow.
Incoming Envelope was approved as part of Unicode 6.0 in 2010 and added to Emoji 1.0 in 2015.