Status Icon Meanings

[CFN-1]

I've looked everywhere I can think of looking and haven't found a list of what the status icons mean. I know it must be in the manual, but where?

The one I'm looking for is the envelope on the left of new posts. Some are grey some are pink shaded. Both have a small arrow on them. What does the grey and pink signify?

Thanks! Frustrated that I can't find it...

EDIT: I'm using the defaults for all settings.

Second Edit: I figured it out. Found the pic files and a posting in another forum that explained each one.

I still wouldn' mind if someone told me where this information is in the manual.