On Thu, Aug 26, 2021 at 3:24 PM Evgeniy Berdnikov via Exim-users < exim-users@exim.org> wrote:
> > If somebody change MX to other host, he should think also how to handle > multiple mailboxes (hosted on "old" place and on "new" one), > and what to do with already stored mails. > Yes, this is something the client/customer and host/provider ideally should be discussing before a change. But if a domain holder changes the domain's DNS records to indicate that delivery should happen at a different MX, it is not, ordinarily, reasonable for a provider to override that. There may be contractual requirements to override it, of course, but in general, overriding DNS leads to confusion and (for the users) "disappearing" e-mail. > There is no such problem if locally submitted mails are always relayed > via smarthost, even if they addressed to local users. To obey your scheme, > smarthost should use only MXes for routing. > > Ideally, all submitted e-mail should be routed on the basis of MX records (or, in their absence, A records). Additionally, you can (and in my humble opinion ought to) perform SPF and DMARC policy lookups to determine whether your server is currently authorized to send e-mail on behalf of the sending domain. -- Jan -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
