If there is no gap between the headers and the body then the parsing will not work
Have seen this with a multipart email where the boundary is directly under the headers - looks like a similar scenario was encountered before as I see this in the codebase
//Updated on 2019-10-12: A line before the boundary marker is not required to be an empty line //if (lines[i - 1] == "" && line.indexOf("--" + findBoundary) == 0 && !/\-\-(\r?\n)?$/g.test(line)) {