On Fri, 31 May 2002, Mark K. Kim wrote: > I can certainly recommend that we keep the current mail service running > for the next month or two after switching over. But getting everyone to > keep checking their new and old mails for weeks is going to be a problem.
Depending upon how mail is implemented for users, and who provides the actual mail service, you have multiple options. > We do have the ability to forward the mails on our current mail service, > but forwarding mails using IP addresses isn't going to work. Is there > another way to forward the e-mails? (I can, of course, forward mails to > my alternate e-mail addresses, but not everyone here has alternate e-mail > addresses. And of course the ones with only company e-mail address are > the ones that are least savvy with computers and will forget to check > both e-mail accounts... :P) If people just check their mail in a shell, and you have two different physical hosts, names can be altered on the two mail servers such that the old server has a "static route" (application layer, mail server setting) for how to deal with mail to the "old domain mail handler" which can include specification of the new server by IP and/or name (with an /etc/hosts entry). This could allow all old mail to automagically be forwarded from the old server (if it should ever happen to be delivered there by misake) to be sent to the new server anyway. You would still need to migrate over all old mail messages mbox-es to the new server, but that would be a one time task. I know I can configure my mail server to be a mail host relay for another ail server - accept mail for delivery, where my server will say to the other mail server, "yes I will deliver this message for you" and then consult my mail server's static handling to see that all mail for this domain should be forwarded to another mail server at another IP address (static routing at application layer). This is much the same as for backup mail servers. If only IMAP is used, then, your fix is much like that for the shell users above - except, you mus be certain the client side IMAP server name actually picks up the NEW IP address with a DNS and not use an old cached IP address beyond the DNS served content "life-span". A failure or fall-back to the old IP address would mean odd clients might try t consult the old server (by IP) for mail. If only POP is used, then you may have a number of pop clients to re-configure, but mail forwarding for new messages may work. HOWEVER, some pop mail clients (mostly in windows and mac land) have a tendancy to assume too much for you and make different local accounts and storage boxes for each popmail server/pickup. You also may have the same problem as above with the IMAP and stale DNS lookup data. Both of the problems with stale DNS lookup data seem very uncommon (from experience) with client machines when compared to the odd ISPs DNS. More common (but still uncommon) is a problem when users use the lmhosts.sam or the /etc/hosts or the macs equiv local hosts file (sorry - cant remember what it is for Mac OS 6.x-9.x) for static IP assignments with host names (consulted before DNS by default.) Of course, I am sure there are other mail clients / MTA combos, and there are likely other solutions with these in mind too. But, it starts with a short "lifetime" for all your DNS settings. Make sure the new "lifespan" for your host lookups are sync-ed over all of your "slave" DNS from your "master" and the changes that are sync-ed actually take effect. Then test your clients to make sure they will use the new settings. Try to time the modification to the NSI/VeriSign/(Your Registrar Company) to happen over the weekend, or over days when nobody is working and then try to make the transition finish before Sunday. With a 1 day expiration on lookup requests, and one day for most root domain changes for authoritative domain DNS, 2 days can easily be sucked up by one weekend and afford you time starting Monday to turn your focus away from the servers and instead to the clients. -ME -----BEGIN GEEK CODE BLOCK----- Version: 3.12 GCS/CM$/IT$/LS$/S/O$ !d--(++) !s !a+++(-----) C++$(++++) U++++$(+$) P+$>+++ L+++$(++) E W+++$(+) N+ o K w+$>++>+++ O-@ M+$ V-$>- !PS !PE Y+ !PGP t@-(++) 5+@ X@ R- tv- b++ DI+++ D+ G--@ e+>++>++++ h(++)>+ r*>? z? ------END GEEK CODE BLOCK------ decode: http://www.ebb.org/ungeek/ about: http://www.geekcode.com/geek.html _______________________________________________ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
