Systems and methods for generating and transmitting multimedia messaging service (MMS) messages are disclosed. In some implementations, a mobile device presents, at a touchscreen, a visual user interface. The visual user interface includes multiple thumbnails and multiple contact blocks. Each thumbnail identifies a file. Each contact block identifies a contact having a messaging address. The mobile device receives, via the touchscreen, a selection of a first thumbnail from the multiple thumbnails. The mobile device receives, via the touchscreen, an indication of dragging the first thumbnail across the visual user interface to a first contact block. The mobile device transmits, responsive to the dragging of the first thumbnail to the first contact block, the file identified in the thumbnail to the messaging address of the contact identified in the first contact block.