In an image transmission apparatus, a reading device reads image data from a document. A setting acquisition section acquires a transmission setting as a setting for transmission of the image data. An image transmission section transmits the image data through a communication device according to the transmission setting. The transmission setting includes a first transmission standard for transmitting a first file containing the image data, a second transmission standard for transmitting a second file containing the image data that is different from the first transmission standard, and a maximum size of the first file transmittable according to the first transmission standard. The image transmission section transmits the first file according to the first transmission standard when a size of the first file does not exceed the maximum size, and the second file according to the second transmission standard when the size of the first file exceeds the maximum size.