mail issues when link is lost

[pbdlists at pinboard.com]

There is more than one way to do it. For example you could put the
following in your /etc/mail/sendmail.mc file:

 FEATURE(`accept_unresolvable_domains')dnl

(pay close attention to the quotes, the first one is a backtick, the
second a single quote!)
and then you'd add something like the following in your /etc/mail/access
file:

 Connect:192.168.0               RELAY
 Connect:192.168.1               RELAY

using whatever your internal IP range is.

If it really is a DNS issue then you might want to pay attention to the
following info and (disabled) configuration in your
/etc/mail/sendmail.mc file:

 dnl # We strongly recommend not accepting unresolvable domains if you want to
 dnl # protect yourself from spam. However, the laptop and users on computers
 dnl # that do not have 24x7 DNS do need this.
 dnl #
 dnl FEATURE(`accept_unresolvable_domains')dnl

To enable that feature remove the 'dnl' at the beginning and end of the
line.

Cheers,

Kurt

On Wed, Apr 14, 2010 at 07:36:01PM +0100, Oluwagbenga Shobowale wrote:
> Thanks what parameters in send mail can I set to ensure sendmail accepts all
> domain mails?
> 
> -----Original Message-----
> From: redhat-sysadmin-list-bounces at redhat.com
> [mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of
> pbdlists at pinboard.com
> Sent: Wednesday, April 14, 2010 6:32 PM
> To: redhat-sysadmin-list at redhat.com
> Subject: Re: mail issues when link is lost
> 
> If the internet link is down, DNS resolving for external domains
> probably won't work either. If sendmail is configured to only accept
> mail for 'existing' (speak resolvable) domains, this could cause such an
> issue. The log files of sendmail (/var/log/maillog) should give you home
> hint.
> 
> Cheers,
> 
> Kurt
> 
> On Wed, Apr 14, 2010 at 06:49:19AM -0400, Carl T. Miller wrote:
> > Okay, so you have one mail server which is running sendmail
> > and it is configured to use your ISP's smarthost.  By default
> > sendmail will queue messages for up to 5 days and will keep
> > trying to deliver them every 4 hours.  Unless you have
> > reconfigured something, it should "just work."
> > 
> > What files have you updated in the /etc/mail directory?
> > Can you let us know what has been changed?
> > 
> > c
> > 
> > 
> > Oluwagbenga Shobowale wrote:
> > > Thanks, but all the clients are windows and point to the local mail
> server
> > > not the ISP. Yes I am using the ISP server as a smart host.
> > > My point is I have configure the outlook to point to the local mail
> server
> > > 192.168.0.1
> > > When mails are sent from the clients it gets delivered to both external
> > > and internal mails as long as the internet link is up. If now only local
> > > domain mails get delivered. External mails at that point don't leave the
> > > clients.
> > > Thanks
> > > Sent from my BlackBerryR smartphone from Zain Nigeria
> > >
> > > -----Original Message-----
> > > From: "Carl T. Miller" <carl at carltm.com>
> > > Date: Tue, 13 Apr 2010 07:45:49
> > > To: <redhat-sysadmin-list at redhat.com>
> > > Subject: Re: mail  issues when link is lost
> > >
> > > Oluwagbenga Shobowale wrote:
> > >> Could you help me out with this. I have a mail server which uses
> > >> sendmail,
> > >> however we relay all our mail to our ISP to save bandwidth as this
> > >> traffic
> > >> is free with our ISP. However, when the link fails we realize that we
> > >> can
> > >> send mails locally but not externally. Is there a way to configure
> > >> sendmail
> > >> to retain  the mails on the mail server and send when the link is
> > >> available.
> > >> Right now the mails remain on the client machine and are not delivered
> > >> to
> > >> the server until the link is back up, well except for the local domain.
> > >
> > > If I understand this, you have a mail server using your ISP's
> > > mail server as its smarthost.  However, your client machine
> > > is not configured to use a smarthost.  I would suggest that
> > > you configure your client machine to use your mail server as
> > > a smarthost, since that will make it easier to troubleshoot
> > > problems and will give you one point where all outbound email
> > > is queued when your connections is down.
> > >
> > > c
> > >
> > >
> > > --
> > > redhat-sysadmin-list mailing list
> > > redhat-sysadmin-list at redhat.com
> > > https://www.redhat.com/mailman/listinfo/redhat-sysadmin-list
> > >
> > >
> > > --
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> > > redhat-sysadmin-list at redhat.com
> > > https://www.redhat.com/mailman/listinfo/redhat-sysadmin-list
> > >
> > 
> > 
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> > 
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