This is in response to a fairly old message on debian-user. I run qmail at home on a Debian system which is connected via dialup PPP (using diald) with a dynamic IP address. I'm not at home right now, so if you need to see exact copies of config files, let me know and I can look them up.
First of all, make up a FQDN. My home dialup system is named "phoenix.local". The /etc/hosts entry will look something like this: 192.168.1.1 phoenix.local phoenix I used ".local" because this will likely never become a valid top-level domain name. I wouldn't want a name conflict. The 192.168.1.1 is the address of one end of the sl0 (SLIP) connection that diald establishes. (This is not the same as the ppp0 (PPP) connection that will be established when diald actually spawns pppd in response to routing requests. The ppp0 interface gets a dynamic IP address from the other end of the phone line.) Once you've made up a FQDN, you can tell qmail what your hostname is. It may not be able to figure it out automatically... which is OK. All you have to do is put your FQDN into the appropriate control file (I think it's "control/me", but it's been a while). With diald, then, that's all you have to do. Purely local mail (such as mail to "[EMAIL PROTECTED]", generated on phoenix) will be handled without causing qmail to do any DNS lookups, so it won't trigger diald. Outbound messages (e.g., to "[EMAIL PROTECTED]") require a DNS lookup, so diald will be triggered (assuming you're using your ISP's DNS servers, which you pretty much *must* do when using diald with a dynamic IP address, since the first packet will be lost due to changes of the local IP address), and then the message will be sent out. Incoming mail will have to be fetched from a POP3 or IMAP server; I use fetchmail for this. Without diald, you'll have to manually tell qmail to deliver the mail when the PPP connection comes up. There's a signal you can send to one of the qmail processes to make it run the queue -- I believe it's signal 14 (SIGALRM), and the process is probably qmail-send, but check the docs to be sure. You can put a line like this into ip-up: kill -ALRM `pidof qmail-send` I actually do this even though I don't have to... my outbound mail volume is low enough that I want each of them delivered ASAP. Hope this helps.