On Nov 8, 2007 10:21 AM, Voytek Eymont <[EMAIL PROTECTED]> wrote: > > [..snip..] > James, Dave, thanks > > between the time I copy it, and, the mail server is transferred, there are > bound to be emails deleted/removed from main server, (as well as new ones > added), >
I've done a few mail server migrations in the past and a bit of DNS trickery helps in not loosing mail. What I would do is set the TTL really low (< 10 mins) for the domain I was transferring (so that all records change their TTL for that domain) 2 or 3 days before the actual migration. On migration day, I would forward ports 25,110,143 (SMTPS, POPS and IMAPS (if you use them) to the new mail server to ensure any new mail is forwarded straight onto the new mail server. You would need to actually resend packets with the source address changed to be the old mail server so that packets are routed back through the old mail server (otherwise it wouldn't work ... A (client) -> B (old mail server) -> C (new mail server) -> A (client) .. it needs to be A (client) -> B (old mail server) -> C (new mail server) -> B (old mail server) -> A (client) ), which means any emails will generate traffic for both, your old & new mail server but since it's only for a period of 48 hours, for me it was never an issue. I would then copy all mail over (using whichever method you prefer .. as suggested by Jeff & David). At this point it's probably a good idea to update the MX record (or the A record, if you want to keep the MX record it points to) so that it points at the new mail server. After 24-48 hours, I would turn off the port forward and monitor the logs to ensure no legitimate email is being received. Hope this helps. Good luck! - Gonzalo -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
