From: Joe Abley [mailto:jabley(a)automagic.org] Sent: Tuesday, June 12, 2001 6:59 AM

ETRN is actually optional with mailbagging, too. Connection attempts will begin shortly after the mailbagging user connects, and will repeat at regular intervals if there is mail to deliver.

The following script may be useful:

for n in ${things_involving_mail} do olof ${n} done

Thanks for blowing my cover Joe! :-) Basically, what we do for CLEAR Net Mail is: 1) Add X-Envelope-To: headers to all inbound messages. This allows for POP3 retrieval of messages for one or more domains/users etc, without having lost the envelope recipients. (Many POP3 <=> SMTP gateways have the capabilities of performing deliveries on these kind of custom headers.) Is POP3 the right mechanism for this? Maybe not, but a lot of our customers want to do just this. And of course, the customer is always right. :-) But a nicer way is mailbagging... For mailbagging: 2a) For mailbagging customers we delivery messages into a separate mailbagging store. This store is designed so that it can efficiently queue large number of messages for each customer. It also (of course) preserves envelope information. 2b) Customers configure a "mailbagging pick-up user-id" via our self-provisioning interface. 2c) When a customers logs on using his pick-up user-id, we kick off outbound SMTP delivery. Once all the mail has been delivered, we check for new incoming mail every 60 seconds, and deliver appropriately. (For as long as the user stays logged on.) Some notes: *** We can do this for both static _and_ dynamic IP assignments. (However, we only offer customers dynamic IP addresses. Static addresses for dial-up customers are bad, for many reasons.) *** Handling dynamic IP addresses (obviously) requires us to keep track, in real-time, of who is assigned what IP address. We do this via a real-time database. Delivery via SMTP is triggered from this database when a user-id record is added that is tagged as a "mailbagging pick-up user-id". *** There are some racing conditions which makes it hard to safely use a standard MTA to implement mailbagging with dynamic IP addresses. Hence, we use a custom MTA. *** We ignore ETRNs. --Olof --------- To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog