gmail 添付できないファイル形式 Some file types are blocked - Gmail HelpThere are a number of reasons why you may find the "This message was blocked because its content presents a potential security issue" error in Gmail. Gmail blocks messages that may spread viruses, like messages that include executable files or certain links. To protect your account from potential viruses and harmful software, Gmail doesn't allow you to attach: Certain types of files, including the
