channel keywords are used to configure SASL use, specifically the use
of the AUTH command, during the SMTP protocol by SMTP based channels
such as TCP/IP channels.
nosasl is the default, and means
that SASL authentication will not be permitted (by the server) or
attempted (by the client). It subsumes both
causes the SMTP server to permit clients to attempt to use SASL
maysaslclient causes the SMTP
server to attempt to use SASL authentication.
causes the SMTP server to insist that clients use SASL authentication;
the SMTP server will not accept messages unless the remote client
successfully authenticates. Specifying
causes the SMTP client to use SASL authentication, and it will refuse
to continue with the SMTP connection if it cannot successfully
mustsasl subsumes both
saslswitchchannel keyword is used to cause incoming
connections to be switched to a specified channel upon a client's
successful SASL use. It takes a required value, specifying the channel
to which to switch.
nosaslswitchchannel is the default,
and means that channel switching is not performed upon a client's
successful SASL use. The
client_auth keyword is used for
client-side SASL authentication to tell the TCP/IP channel which
CLIENT_AUTH section of the
to read to get the username and password to use to authenticate to the
remote system. If this option is not specified, the
CLIENT_AUTH section is used.
See Section 14.4 for further discussion and examples of use of these channel keywords.