sendmail question

[SykkN]

I am running Red Hat 7.2 connected to a cable modem using DHCP. Whenever I send an e-mail message to user@my.ip.address I get delayed mail messages back and eventually just an error saying the mail could not be delivered. Is there something specific I need to do with my sendmail.cf file to get it to work with my dynamic ip address?

[Syngin]

I think you need to qualify sendmail with a real domain even if its only a free one from dyndns.org. Apache is like that too.

You might be able to set it to @localhost maybe. Can't send email to a straight ip though. (to my knowledge)

[PLBlaze]

While RFC documents permit using IP address in email, it has many shortcomings as opposed to using FQDN names.If you decide to use your IP then it must be enclosed in [] as per RFC, eg. user_foo@[1.2.3.4].For more information see www.sendmail.org.Hope (http://www.sendmail.org.Hope) this helps.

[bdl]

While it's true that you have to have a FQDN to relay mail out into the 'real world', you can certainly set your server up to just route on your own local network or even on your own machine. I'd recommend, however, switching to something a little easier to configure and run, like Postfix or Exim. Sendmail, IMHO, is just too much trouble for a single machine or basic user, you'll find the other servers to be much lighter when it comes to system usage, more secure and easier to configure / keep tabs on. Luck!