First, due to historical reasons, foreign companies representing high-rise buildings banned QQ from the beginning. Older people on the Internet still remember MSN. At that time, the office computers of many multinational companies and Fortune 500 companies blocked QQ even if they could access the external network. Everyone uses MSN to chat, so QQ mailbox was discriminated from the beginning. Second, for brand reasons, QQ is a brand with heavy entertainment temperament. QQ mailbox is implicated in it, which will be inappropriate in formal business occasions. Just like most business cards don't print QQ number, QQ is a strong personal application brand, but it is not serious enough in formal business occasions. Although the mail brand is particularly illusory, it is one of the business etiquette, similar to some companies requiring to wear a suit to work. Thirdly, there are a lot of media endorsements about "being discriminated against for leaving QQ email", which have been talked about countless times by major media and forums. 88% people show some contempt for QQ email, "and if the resume is sent by QQ email, it means that this person is probably born after 90". The first recruitment network even said sternly that it is not serious to send a resume by QQ email. The attitude of the media has spread the influence of discrimination against QQ email to the whole society. Fourthly, it is a widespread hidden rule that HR circle discriminates against resumes left in QQ mailbox. HR should look at a large number of resumes for many years, and simply block out some resumes left in QQ mailbox. This is a simple and rude screening method. As for the reasons, HR can find out various reasons. For example, QQ email is an accessory product of chat tools, and most people's QQ email accounts are a series of numbers or strange nicknames, indicating that candidates have not clearly divided their work and life, and their attitude towards resumes and work is not sincere.