Tim: >> One problem with such simple masquerading is when you send out a mail >> using a local LAN address, it fakes your local domain to be the ISP's >> domain, and that constructed address happens to be the same address as >> someone else on your ISP. Gene: > That is -not- correct. The outside world will see the ISP sendmail > outbound MX and it will have a unique and reversable IP. The internal IP > may show up in a received line and plays zero roll at all. It is not a > problem in any way. I'm not talking about IP addresses, I mean email addresses. Presume that I am tim@localhost on my machine, and I masquerade my mail to change localhost to the domain name of my ISP (e.g. example.com), and I (now) send out my mail as tim@xxxxxxxxxxx, to save me from configuring my mail clients. But, *I* shouldn't do that, because I am not user "tim" on my ISP, some other person has that ISP mail account. In general, you can masquerade with your own domain names quite freely (swap an non-public internal domain for a real external domain name), but you shouldn't simply use someone else's domain (such as your ISP's). Even if you happen to use the same username as your ISP, it's still potentially a problem, because you can start sending out mail from other addresses (postmaster, root, etc.), which you won't be authorised to do. Masquerading has to be done with due care, as with just about all aspects of running a mail server attached to the public internet. -- [tim@localhost ~]$ uname -r 2.6.27.25-78.2.56.fc9.i686 Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
