On Wed, 22 Jun 2005 17:57:52 BST, Tony Finch said:
You don't need a central MX if each site MTA knows which users are at which sites. Incoming email may have to take an extra hop if it comes in to the wrong site, but that's a consequence of the specification that no implementation can fix.
Exactly. The problem is that Andrew already labeled that as "suboptimal":
Doesn't solve the problem of an email being sent to the wrong mx server (all mailservers would need to be able to handle an email delivered to it even if the account isn't local...more centralization). This would solve some of the problems with one centralized server farm if there was a globally distributed network of core mail servers, but sacrifices autonomy.
He *might* be able to sell the various branch offices on a solution that uses LDAP or similar (Andre Oppermann suggested qmail-ldap), where each branch manages its section of the LDAP tree, and the only centralized part the offices would have to trust HQ to do is possibly run a robust redirector to the various LDAP servers. Sorry Andrew - but that's probably the "best suboptimal" that you'll be able to actually deploy within the context of SMTP....