I have configured sendmail to handle internal and external mails over the network. Internal mails work fine. But the problem with external mails is that I can send external mails only when I am connected to internet. If not connected it gives following error:

Relaying temporarily denied. Cannot resolve PTR record for x.x.x.x

I have already enabled relay in /etc/mail/access and /etc/mail/relay-domains for 192.168.0.

Please HELP!!!

Well that is suppost to do that, how can u send external emails if you aren't connected to the internet?

yeah how?

it may send them the next time you connect

The DeliveryMode variable specifies how mail is to be sent. The default, b or background, will gather the message, verify the recipient is deliverable (which when offline, it's not and returns the error message you are getting), forks a copy of itself and delivers the message in the background. If you want all messages accepted and delivered later, change DeliveryMode in sendmail.cf to q for queue-only. The time between mail queue dumps is set with the -q option to sendmail. Keep in mind this only works when sendmail is run as a daemon. Well, not really. You can manually run sendmail periodically with the -q switch to dump the queue.

By the way, the only time any of the relay parameters mean anything is when your system is acting as a mail relay between two other systems. Has nothing to do with local users. Won't hurt though.