Receiving frustrating and horrible emails from clients is all in a days work for a lot of designers. Many people fail to appreciate the skill and talent that can go into design work, which can lead to emails asking questions such as "I got your invoice... it seems really high. Why did you charge so much?," a question that many other professions would never be asked.
Joshua Johnson, a writer at Creative Market has to put together a list of the most frustrating emails a designer can receive and they are pretty funny. We are sure those in the industry can relate.