Delivery Status Notification (Failure)

linuxlover.chaitanya · 08-10-2010, 01:06 AM

Aah..Eric missed that point. Yes cron can send system mails. Thats was a good look Eric.

Xanios · 08-10-2010, 01:44 AM

Hi Eric,

i got this:

Code:

nagios@ubuntu:~$ cat .forward
cat: .forward: No such file or directory

Oh okay, thats not from Nagios. Is from deamon (cron) to root user..
But why do they need to send to root user?

thank you

EricTRA · 08-10-2010, 01:46 AM

Hello Xanios,

You need to create that file. You could do it like this

Code:

echo "youremail@gmail.com" > .forward

when in your home directory.

The cat only shows you the contents of the file, since it's not there you get the error you posted.

Kind regards,

Eric

r3sistance · 08-10-2010, 01:47 AM

Quote:

Originally Posted by Xanios

But why do they need to send to root user?

Quote:

Originally Posted by r3sistance

It could be automatic log reports or some other services trying to send information to root.

The bold section would be my guess, I often get e-mails from the system with the title "Logwatch for <hostname> (Linux)" I suspect it will be a similar service that is running in cron or the such that you have been hit by. Mine sends directly to root@<domainname> however, so I suspect at some point I had reconfigured it.

EricTRA · 08-10-2010, 01:49 AM

Quote:

Originally Posted by Xanios

Oh okay, thats not from Nagios. Is from deamon (cron) to root user..
But why do they need to send to root user?

thank you

Hello,

There are various system services and daemons that mail errors or warnings to the system user that runs them. Most of them just write to log files and it's up to you to check your logs, but there are some that mail to the local user. Since you have set up your system to relay all mail to your gmail account it's best to include also the system mails.

Kind regards,

Eric

Xanios · 08-10-2010, 02:03 AM

Oh i see.
For a minute i thought something had gone wrong with my postfix again :X
Because Nagios have stopped sending email notifications to my gmail..
But i guess they have sent finish the mails so thats why they stopped sending..

EricTRA · 08-10-2010, 02:05 AM

Quote:

Originally Posted by Xanios

Oh i see.
For a minute i thought something had gone wrong with my postfix again :X
Because Nagios have stopped sending email notifications to my gmail..
But i guess they have sent finish the mails so thats why they stopped sending..

Hi,

If you doubt that postfix is functioning just look at the log for errors, send a test mail from the command line:

Code:

mail -s "Testmail from your server" yourname@gmail.com

press CTRL-D and enter to send the mail, and check the logs again to see if any problems arise.

Kind regards,

Eric

Xanios · 08-10-2010, 06:24 AM

Hi,

i did what you have told me.

My last few lines in log file:

Code:

Aug 10 19:22:48 ubuntu postfix/smtp[2752]: 9A9BD40A81: to=<xanios@gmail.com>, relay=smtp.gmail.com[74.125.53.109]:587, delay=4.2, delays=0.13/0.1/2.1/1.9, dsn=2.0.0, status=sent (250 2.0.0 OK 1281439381 33sm12606005wad.18)
Aug 10 19:22:48 ubuntu postfix/cleanup[2750]: DEBC340A83: message-id=<20100810112248.DEBC340A83@ubuntu>
Aug 10 19:22:48 ubuntu postfix/bounce[2755]: 9A9BD40A81: sender delivery status notification: DEBC340A83
Aug 10 19:22:48 ubuntu postfix/qmgr[2744]: 9A9BD40A81: removed
Aug 10 19:22:48 ubuntu postfix/qmgr[2744]: DEBC340A83: from=<>, size=1781, nrcpt=1 (queue active)
Aug 10 19:22:49 ubuntu postfix/smtp[2752]: certificate verification failed for smtp.gmail.com[74.125.53.109]:587: untrusted issuer /C=US/O=Equifax/OU=Equifax Secure Certificate Authority
Aug 10 19:22:53 ubuntu postfix/smtp[2752]: DEBC340A83: to=<xanios@server.com>, relay=smtp.gmail.com[74.125.53.109]:587, delay=4.2, delays=0.05/0/2.2/1.9, dsn=2.0.0, status=sent (250 2.0.0 OK 1281439385 z1sm7657360wfd.15)
Aug 10 19:22:53 ubuntu postfix/qmgr[2744]: DEBC340A83: removed

I guess it should be okay? (:

EricTRA · 08-10-2010, 06:43 AM

Hi,

Code:

Aug 10 19:22:53 ubuntu postfix/smtp[2752]: DEBC340A83: to=<xanios@server.com>, relay=smtp.gmail.com[74.125.53.109]:587, delay=4.2, delays=0.05/0/2.2/1.9, dsn=2.0.0, status=sent (250 2.0.0 OK 1281439385 z1sm7657360wfd.15)
Aug 10 19:22:53 ubuntu postfix/qmgr[2744]: DEBC340A83: removed

The first line states that the message was sent correctly:

Code:

status=sent (250 2.0.0 OK 1281439385 z1sm7657360wfd.15)

and the last line removes it from the queue.

Destination was xanios@server.com, so I assume you've set up the .forward file holding your 'real' email address in it?

So it should be OK. Did you receive the message correctly?

Kind regards,

Eric

Xanios · 08-10-2010, 06:58 AM

Ya, i did set up the .forward file holding your 'real' email address in it(:

And yup, i received the test mail in my gmail

Just wondering..how come it removes it from the queue?

EricTRA · 08-10-2010, 07:24 AM

Hello,

So that confirms that it works! Great!

Now, for your question. That's the way Postfix works with queues,
hold
incoming
active
deferred

and the qmgr daemon takes care of those queues, moving the messages from one to another if undeliverable to try later, moving them to hold if you tell the qmgr to do so using the postqueue command, and so on.

Better description from the man page of qmgr:

Code:

MAIL QUEUES
       The qmgr(8) daemon maintains the following queues:

       incoming
              Inbound mail from the network, or mail picked up by the local pickup(8) daemon from the maildrop directory.

       active Messages  that  the queue manager has opened for delivery. Only a limited number of messages is allowed to enter the active queue (leaky
              bucket strategy, for a fixed delivery rate).

       deferred
              Mail that could not be delivered upon the first attempt. The queue manager implements exponential backoff by doubling the  time  between
              delivery attempts.

       corrupt
              Unreadable or damaged queue files are moved here for inspection.

       hold   Messages that are kept "on hold" are kept here until someone sets them free.

Look at the man pages for:

Code:

man postsuper
man postqueue
man qmgr

Kind regards,

Eric

Xanios · 08-10-2010, 08:20 AM

hey thank you for the clear explanation!(:

everytime i saw the 'removed from queue', i thought it was something bad, like the send email couldn't be sent etc. haha(:

this:

Code:

Aug 10 19:22:49 ubuntu postfix/smtp[2752]: certificate verification failed for smtp.gmail.com[74.125.53.109]:587: untrusted issuer /C=US/O=Equifax/OU=Equifax Secure Certificate Authority

is nothing important i suppose? sorry keep asking questions >.< but i'm just doubtful..kept saw this everytime i sent a test mail. :X

in Nagios, once all notifications of downed services/hosts have been sent, it would stop sending right? because in my gmail i no longer receives any email notifications from nagios, even though those services are still down.

thank you once again!

EricTRA · 08-11-2010, 12:18 AM

Quote:

Originally Posted by Xanios

hey thank you for the clear explanation!(:

everytime i saw the 'removed from queue', i thought it was something bad, like the send email couldn't be sent etc. haha(:

this:

Code:

Aug 10 19:22:49 ubuntu postfix/smtp[2752]: certificate verification failed for smtp.gmail.com[74.125.53.109]:587: untrusted issuer /C=US/O=Equifax/OU=Equifax Secure Certificate Authority

is nothing important i suppose? sorry keep asking questions >.< but i'm just doubtful..kept saw this everytime i sent a test mail. :X

in Nagios, once all notifications of downed services/hosts have been sent, it would stop sending right? because in my gmail i no longer receives any email notifications from nagios, even though those services are still down.

thank you once again!

Hello,

I wouldn't say that the certification error is not important. If you receive mails from your system then you can solve that error without any pressure. I'm not sure however why you get that error.

About the Nagios notifications not going out, if the services are down then you should receive the notifications. If you don't then that's bad.
Is Nagios running OK? To what address and as what user do you send the notifications? Force a notification and check the log right after that to see if it gets send out by postfix.

Kind regards,

Eric

Xanios · 08-11-2010, 12:31 AM

Hi,

I don't think Nagios is running OK? Because most of the services are still down, and i no longer receives email notifications from nagios. I wonder why. They simply just sent once and after that stopped?

How to force a notification?

Thank you.

EricTRA · 08-11-2010, 12:48 AM

Hi,

It's been some time since I used the 'plain' version of Nagios (I have Groundwork installed which is build around Nagios since my coworkers don't have Linux experience) so I'm not sure how to force notifications with it.

Are you sure you set your notification and check periods correctly so that checks are performed at regular intervals?

I believe you can check if Nagios is running with:

Code:

/etc/init.d/nagios status

or whatever your startup script is named.

Kind regards,

Eric