Red Circle, White Cross - Means?

I have two Yahoo accounts on Zimbra Desktop. One of them has a red circle with a white cross next to the account name. When I hover on it I learn that the status is "error".

What can I do about this?

Can I force a second attempt to download all that stuff from Yahoo?

Can I search somewhere for the error?

My C: drive is down to a few hundred megabytes, can I get Zimbra to move everything to a new location somehow?

Or would it be something I should tell Yahoo about - my account there is screwed somehow?