Sendmail and intraprocess communication

[Steven Sipes_1]

I am currently reconfiguring sendmail to operate in queue mode only. I'm doing this by renaming the /sbin/rc*.d scripts so that they don't execute. I'm following that with a call to sendmail -q via cron. However, I'm told that disabling daemon mode on an HPUX 10.20 system will break some intraprocess communications within the OS itself. Anyone know anything about this?

[harry d brown jr]

Steven,

I have never heard of that -> "...system will break some intraprocess communications..."

I have 10.20 servers without sendmail running and they aren't "broken".

Check with the person that made that statement, maybe they can clarify it.

live free or die
harry

[Jordan Bean]

I have sendmail running as a client in daemon mode on the loopback interface. This means that it doesn't receive messages from the network (only from loopback if required) and forwards everything to another server.

To restrict port 25 to loopback interface, set these in /etc/mail/sendmail.cf:
O DaemonPortOptions=Port=smtp,Addr=localhost
O PrivacyOptions=goaway,restrictqrun

To configure sendmail as a client to forward all messages to another server, you may either set the SENDMAIL_SERVER_NAME in /etc/rc.config.d/mailservs to the desired hostname, or in /etc/mail/sendmail.cf set DS, DH, and DM to $m (where DNS will resolve the MX records for the local domain). I recommend the latter as the former does not set DS, only DH and DM.

Review this for more details:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x94c40bce6f33d6118fff0090279cd0f9,00.html

[Steven Sipes_1]

Thanks for all the responses. I was fairly sure that setting sendmail to daemon mode wouldn't break anything. I also really like the thought of making the necessary changes in sendmail.cf instead of mucking with the rc*.d scripts. That way patches/updates shouldn't break it. Right?

[Bill Hassell]

You are correct that changing scripts in /sbin/init.d (/sbin/rc*.d contains only symlinks). To turn off (or on) subsystems and applications, you edit the configuration scripts located in /etc/rc.config.d. So to disable sendmail:

/sbin/init.d/sendmail stop

Then:

vi /etc/rc.config.d/mailservs and change:

export SENDMAIL_SERVER=1
to
export SENDMAIL_SERVER=0

Now, sendmail will no longer start on reboot and you don't have to change anything in /sbin.

[Steven Sipes_1]

So, just to clarify...
On both HPUX10.20 and HPUX11.00, I can modify /etc/rc.config.d/mailservs so that SENDMAIL_SERVER=0. Then, if I put in a cronjob (perhaps in root's crontab) that calls sendmail with the -q option, the system will no longer be running sendmail in daemon mode but will still process both local mail as well as outbound mail.

Using this method will keep me from having to modify anything in /sbin/rc*.d and /sbin/init.d which is good because they may be changed during a patch.

Do need to change anything in sendmail.cf?

Thanks everyone for your help.

[Steven Sipes_1]

Wow! I just saw that the last reply was from Bill. Bill won't remember me, but I remember him from both the Atlanta response center as well as a talk in California circa 1998. Same Bill?