Raul: > I think the simplest way of dealing with messages in flight across > mail transport agent changes would be to define a simple queue > structure to hold the messages across mta installations.
It's true that an MTA change is currently difficult to do correctly. I recently did this for chiark (which handles about 20,000 deliveries a week). I installed Exim (the new MTA) with --force-conflicts, and fixed up the /usr/sbin/... links by hand to point to Smail. I ran Exim for testing for a week on a different IP address, with both it and Smail delivering to local mailboxes. Then I switched the main SMTP reception and /usr/sbin/sendmail to Exim, leaving Smail to deliver its queue. Smail had some messages it had wedged on, and I got it to deliver them to `localhost' as a smarthost (and turned Exim's verification off for messages from localhost). Then I removed Smail, and redid dpkg --install exim for good measure. How much effort do we want to do to make this easy and working ? Getting it right will be _hard_, even if we don't want to allow parallel running. > Policy should be that a mail transport agent postrm should move any > undelivered mail messages into this queue with this format and that > the postinst should move messages from this queue to the new mta's > queue. ssmtp would require special effort (either refuse to install > using a check in preinst or a queue run job which checks the error > code from /usr/sbin/sendmail). An mta shouldn't be considered > installed until all messages have been succefully moved out of this > temporary queue (technically, it's ok if unreasonable messages get > bounced, and this should be considered a success). This would be a reasonable way to go about things. > Probably the simplest mechanism is a directory with one file > per message, first line being envelope from address, subsequent > line(s) being destination address(es), then a blank line, then > the message (headers and all). Please can we use batched SMTP ? Both Smail (the current recommended MTA) and Exim (the one we'll probably be recommending eventually) support this for input and output. Ian. -- E-mail the word "unsubscribe" to [EMAIL PROTECTED] TO UNSUBSCRIBE FROM THIS MAILING LIST. Trouble? E-mail to [EMAIL PROTECTED]
