a long while back i posted a query about how to get mail delivery (with postfix) working on a ipmasq lan with the gateway being on a dialup, dynamic ppp connection to the internet. for the benifit of the list archives here is the solution (thanks to Allan Wind for the advice):
it pretty much boils down to setting up a canonical mapping for any users who will send mail the outside, so the following are added to postfix's main.cf: recipient_canonical_maps = hash:/etc/postfix/canonical_receiver sender_canonical_maps = hash:/etc/postfix/canonical_sender canonical_reciever is actually not necessary unless you want say mail [EMAIL PROTECTED] to work. canonical_sender is used to translate local users email address from [EMAIL PROTECTED] to [EMAIL PROTECTED] like so: user [EMAIL PROTECTED] canonical maps have to be compiled with postmap /etc/postfix/canonical_sender the myorigin setting of main.cf must NOT be set to anything resembling your isp's domainname, if you do the next time cron mails root it will go to your isp's root account not yours. i have found it best to leave mydomain to the internal domain names used for the private lan, setting it to anything else tends to cause more things to break, especially if you have a couple machines and you want to send mail between them without going through the isp. myhostname does not really matter so long as you dont set the other variables (such as myorigin) to it setting it to something useful such as yourispusername.yourisp.com will make it easier for someone to contact you if something goes wrong. I added $myorigin and the local machine's short hostname to mydestination to ensure local mail does not get relayed to the isp. i also have a couple machines in the lan i wanted to be able to send mail to (for private accounts) so i added a transport table to prevent things from being routed to the isp (all boxes relay to the gateway and the gateway relays to the ISP) all that seems to be required is the following in /etc/postfix/transport (compiled with postmap) internal.domain smtp: .internal.domain smtp: hostname.internal.domain local: localhost.internal.domain local: unless dns is running for the internal network you also have to have: disable_dns_lookups = yes in main.cf for incoming mail use fetchmail of course.. that is pretty much it. -- Ethan Benson
