[Users] Exclamation mark after Inbox

[osterd at gmx.de]

Hey,

can anybody please explain to me what an exclamation mark in brackets after the
Inbox folders means?

I observed it a couple of times now but I could see no clear relation as to
when it occurs. I only found out that it vanishes if I read the most recent
mails.

What does trigger it? I tried searching for it in the documentation but my
search turned up empty most likely because I didn't really knew what to search
for.

Best H.