richard.lin@wamis0.cse.nsysu.edu.tw:
> Dear All,

> The following error messages are shown in the log file. Can anybody know how
> to solve it? Thanks a lot.

> --------
> Feb  7 09:46:39 BSD sendmail[175]: starting daemon (8.11.3nb1):
> SMTP+queueing @00:30:00
> Feb  7 09:46:39 BSD sendmail[175]: NOQUEUE: SYSERR(root): opendaemonsocket:
> daemon MTA6: can't create server SMTP socket: Protocol not supported
> Feb  7 09:46:39 BSD sendmail[175]: NOQUEUE: SYSERR(root): opendaemonsocket:
> daemon MTA6: optional socket disabled

It the string "MTA6" leads me to believe that sendmail is trying to
open an IPv6 socket, and that you system is compiled without IPv6
support.

I would interpret it as an "informational" message, rather than an
error message. It's just a notice that the program cannot provide
transport over IPv6, that's all.

To get rid of it (and get rid of all sendmail IPv6 transport) try to
remove (or comment out) the line

  O DaemonPortOptions=Family=inet6, address=::, Name=MTA6

in your /etc/mail/sendmail.cf file and see if that helps (it should),
or better still, change the settings in the corresponding .mc file
(using the DAEMON_OPTIONS instruction), and re-build the sendmail.cf
file.

Does it work with IPv4 as expected?

				Best regards,
				  /Liman
#----------------------------------------------------------------------
# Lars-Johan Liman		! E-mail: liman@autonomica.se
# Senior Systems Specialist     ! HTTP  : //www.autonomica.se/
# Autonomica AB, Stockholm 	! Voice : +46 8 - 615 85 72
#----------------------------------------------------------------------