Why does Avast not provide the option to remove executable files attached to emails? AVG does this.
Removing a file just because of its file extension isn't smart AV work but dumb discrimination. Not that it is infected.
Receiving an attachment of any file type isn't an immediate threat anyway. You have to open/run it and regardless of what file type it is.
You should
never run/open an attachment directly from your email client, save the attachment to your hard disk. That action should trigger an avast file system shield scan (depending on file type), the same is true if you try to run that .exe file after saving it to your hard disk.
Education, Education, Education, should be top of the list.