Sendmail daemon is inactive, but still i can send emails

UNIX AIX
1

Hi,

I did setup sendmail on one of AIX LPARs. Its working as expected. But, would like to clarify something with you all.

I stopped the sendmail daemon on AIX LPAR, now it is inactive(&commented it on /etc/rc.tcpip ). But still, am able to send the emails even after stopping daemon.

[root@aixlpar]/>lssrc -s sendmail
Subsystem         Group            PID          Status
 sendmail         mail                          inoperative

[/CODE]

As per my understanding;
in order to "send" mail, the mail server is not required to accept connections on port 25 or any other port. Listening mail server is used for receiving mail.

is that correct ?
if yes, so i can disable the sendmail daemon on aix forever right ?

another question is
i see some error/entry in mail logs all the time.but, I do not see this error after stopping the sendmail daemon.

"
Jan  1 10:10:10 AIXLPAR mail:info sendmail[1234567]: xxxxxx4: to=myuser.name@domain.com, ctladdr=root (0/0), delay=10:10:39, xdelay=00:02:15, mailer=esmtp, pri=35000, relay=domain.com., dsn=4.0.0, stat=Deferred: Name server: domain.com.: host name lookup failure"

Please let me know, if this error can be ignored.

2

If you don't care that mail is sitting in your machine's outgoing queue and is will not be delivered, then you can ignore the message.

And, since you have turned off the sendmail, why are you surprised that you are no longer seeing the error messages it would print if it were running?

3

Thanks for the reply Don.

coming to my 2nd question
Yeah you're correct. I stopped the sendmail, should not see any error messages related to mail.

but i did not know why got that error message.

my first question was,
i was able to send emails even after stopping daemon. I believe my assumption(mentioned first post) was correct. But, i wanted to double check with experts.

4

You say you are able to send e-mail after you disable the sendmail daemon. That is not surprising. Tools that add e-mail messages to be sent out are independent of the sendmail daemon that would pick up those messages after they are queued and forward them to the desired recipients.

Did anyone receive any of those messages that were sent after you disable the sendmail daemon, or are they just sitting, unprocessed, it the outgoing mail queue?

5

yes Don, those emails were received by desired recipients. one more last question for now, can I just disable send mail daemon on AIX servers ?
i mean, if we can not use AIX LPAR as mail server. I just want to send email alerts from my scripts to desirable recipients. just need some idea on how others doing, in what case they enable this daemon.

thanks for your time.

6

You can explicitly configure sendmail to not require a daemon, example
But if it seems to work already, you can disable the daemon.
--
As an alternative, there is a way to have a sendmail daemon running that only listens to localhost.
In /etc/mail/sendmail.cf add , Addr=127.0.0.1 to the

O DaemonPortOptions=...
7

Thanks for the reply MadeInGermany. I like your idea, will give a try. Thank you.