What is the difference between Soft Bouncing and Hard Bouncing?

What is the difference betwen hard bouncing & soft bouncing in Yahoo Groups?

• I can't believe I can't find the answer to this very basic question from Yahoo Groups help.

• Answer:

  A soft bounce is a message returned due to a temporary delivery failure -- for example, a full mailbox. A hard bounce is a message returned to Yahoo! Groups due to permanent delivery errors -- for example, an invalid email address. If a member is listed as a hard bounce, they should check with their email provider to make sure that their email account is working properly. There are a couple of ways that members can reset their bouncing status: -Groups automatically send reactivation requests to bouncing members, every three days. If the member replies to this notice, the account will be automatically reset and Groups will resume message delivery to the address.