The exception that is thrown when the proxy server rejects authentication data sent the client or does not support any of the authentication methods supported by the client.
The exception that is thrown when the proxy server rejects the proxy connection request from the client.
An abstract parent for all exceptions that are thrown when the proxy server returns negative reply during negotiating with the client.
Contains properties which define the proxy server settings.
Defines the available modes of establishing connection with a mail server via a proxy server.