The Internet help section
provides general assistance. This section provides help specific to email.
While email is generally one of the most reliable communication mediums known,
it is complex enough that
it occasionally runs into technical problems. The following sections describe
common email problems and suggested solutions.
Resources. You can find a list of the error control
codes that email servers send back in response to a failed email in Section
4.2.2, "Numeric Order List Of Reply
Codes", of RFC