Today, some, but not all of the unread mails had a little yellow sun-like wheel symbol in the left margin of the inbox thread pane. The symbol appears in the same area where other mails can have small arrows indicating that I have answered to a mail. When I click any such mail, it changes to the read state (normal typeface as opposed to bold), and the wheel also goes away. While trying to ask this question, I had to request a password reset, and after receiving that mail, the last remaining unread message that had this wheel, no longer had it. I am thus unable to make a screenshot demonstrating the symbol. However, it consists of a circular yellow area with a large number of short black lines in the radial direction, placed evenly along the perimeter inside the yellow area, forming a ring or radial lines. If you know about the symbol, what do you call it? What does it try to tell? In case it matters, I use an IMAP account.