Clarifying sendmail configuration - sendmail-client offline

UNIX Solaris
1

Hi all,

I have read about sendmail running as 2 separate process.
1 as a MSP, and the other as the real daemon or MTA.

In my current configuration,

  • the sendmail-client is disabled.
  • Both submit.cf and sendmail.cf are left as default untouch
  • I do not specified any mailhost in my host file.
 
 -bash-3.2$ svcs -a | grep sendmail
disabled       Feb_27   svc:/network/sendmail-client:default
online         Feb_27   svc:/network/smtp:sendmail

However, on doing a

 
 echo abc | mailx -v -s "test" test@testabc.com

I can still see my mailx sending mail to a local port (local sendmail daemon), before actually being forwarded out to the mailserver "testabc.com"

q1) if my sendmail-client is disabled, does mailx still use submit.cf in anyway and does it still push the mail to /var/spool/clientmqueue or it is send directly to the local sendmail daemon (listen at port 25) ?

does 1 send to port 25 1st and upon failure, goes into clientmqueue or it is another way round ?

q2) if I do not set a mailhost, and neither do I set any configuration in sendmail.cf, is it still normal to have the local sendmail daemon send out to the right mailserver "testabc.com" ? -- does that means it done a DNS lookup for mx record of "testabc.com" ?

Regards,
Noob

2

I think:
mail/mailx execs to sendmail in submit mode. If there is no sendmail client daemon running, it connects via port 25 to to the main sendmail daemon (MTA).
q1) mailx uses submit.cf but does not use clientmqueue.
q2) yes, by means of DNS MX and A/AAAA records, the MTA can connect to them via port 25.

3

Hi MadeinGermany,

Thanks for your reply.

Do you mean that mailx direclty send to the sendmail MTA daemon (without going to the clientmqueue) ?

Regards,
Noob

4

Yes I think so. It execs to sendmail in submit mode. There is no need to spool the mail because it runs in the foreground.