I am surprised that your test case works at all. The EXAMPLES section of MIME::Entity specifies that the data field is a reference to an array of strings (lines). Your have a string. I suspect that your problem has nothing to do with 'dot stuffing'. The 'Output' section of the same document specifies that 'stringify' (as_string) returns the entity exactly as print would print it. (I take this to mean that any 'stuffing' is removed.) In your case, a long line is split into two. The URL is split over the two lines. It appears that the module uses the '=' (at the end of the first line) to indicate this split. Are you sure that you are extracting the URL correctly in this case?