This is the G-Mail login logo. There is a rectangle which contains an "M" that uses the left and right of the rectangle to form the left and right of the "M". There is an arrow through the top that points down.
This Gmail Login icon is made in flat color style
. This format was developed by Icons8 designer team and became immensely popular for use in web and mobile applications. Feel free to download this icon in PNG format for free, or unlock other formats for $5. Unlike other icon packs that have merely hundreds of icons, this monster icon pack contains 6,000 icons, all in the same style and quality.