[lug] Cron problem

[rm at fabula.de]

On Fri, Jun 18, 2004 at 01:53:18AM -0600, Mark Sweitzer wrote:
> 
> I've been using Cron on a few Fedora-9 servers to run automated daily
> backups.
> For a few years, Crontab has been configured with the "mailto=" command
> directed to an address in a domain not related to the respective host
> machines. (The hosts have retained the default "localhost" name, with no
> domain association.)
> 
> Recently, these servers have stopped sending confirmation messages from cron
> daemon to this designated email address, all simultaneously on the same day,
> and never again since that day. These servers are in different cities and
> not WAN-connected. The log files for cron indicated that the attempted
> message sending everyday was undeliverable.

I'd suggest a systematic approach (you might have done this allready):

1) Are you shure cron runs? Try to inject a cronjob that either creates a
   local file or sends mail to a local user (mailto=root).
   
> In an attempt to troubleshoot, I changed the "mailto=" to addresses from an
> entirely different domain, yet the results were still unsuccessfully
> delivered. So now I'm stumped.

2) Any mail logs? I'm a Debianista but /var/log/mail* would be a good place
   to check.

3) Can you send mail from these boxes when you are logged in?

> 
> Any clues on this would be helpful. Sendmail service is running on these
> machines. How does sendmail utilize an SMTP server to access up-to-date DNS
> MX records to direct these attempted messages, and why did it work
> successfully on several machines before, over a span of years? 

Hmm, the MX records are retrieved by means of DNS lookups, not from an
SMTP server .... 
You can easily test this:

 $ dig your.target.domain.here mx

 

> I never
> configured them to a specific SMTP server address. 

You don't need to do this. What's your local mailer (sendmail/exim ....)

> These machines are inside
> of a firewall and have hard-coded NAT IP addresses and nameserver addresses
> in their ifconfigs.

Are these boxes all behind the _same_ firewall? Maybe the firewall (or your upstream
provider) blocks outgoing mail traffic?

I guess a close look at your mail logs should answer most of these questions.


HTH Ralf Mattes

> 
> Thanks for any assistance on this.
> 
> Mark

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