Noel, Inline. On Fri, Jun 15, 2012 at 11:25 AM, Noel Jones <njo...@megan.vbhcs.org> wrote:
> On 6/14/2012 8:38 PM, Adam Bradley wrote: > > I have a situation where email delivered to a single namespace needs > > to be delivered to a user who could be in one of a number of > > downstream system (but we don't know which one > > that sounds... broken. > Agreed, its pretty unusual. > > > I was wondering if > > I could use "Callback Verification" > > http://en.wikipedia.org/wiki/Callback_verification to achieve this? > > No. Although postfix has address verification, there is no > mechanism to try N servers until success, nor a method to store > which server accepted the recipient. > > I'll strike that option from the list. > > > > Ideally, I'd like to avoid the use of a look up table. > > Why? A lookup table is exactly what you need. > > Given I now know you can't achieve the approach above I'll pursue using a lookup table. However, with around 5 million users, address verification was looking like the best option. > > > > To recap, the mail flow would be as follows > > > > (In the case where the user exists, send to the appropriate MTA) > > -> u...@mail.org <mailto:u...@mail.org> => Callback Verification on > > recipient -> MTA hosting 1.mail.org <http://1.mail.org> (miss, user > > does not exist in this namespace) > > > > -> MTA hosting 2.mail.org <http://2.mail.org> (hit! deliver to > > u...@2.mail.org <mailto:u...@2.mail.org>) > > > Sorry, but this sounds to me like an accident waiting to happen. I > would /strongly/ recommend getting a proper recipient list and > populating transport_maps with a user->host mapping. > > > My only concern is scalability, is there anything you can point me to regarding transport_maps and sizing/scalability? > > -- Noel Jones > Thanks Noel! Sincerely, Adam | Identity Concepts | a: PO Box 451 Hamilton, | Brisbane, QLD 4007, Australia | m:+61 419 637 518 | e: adam_j_brad...@identityconcepts.com.au | im: adam_j_brad...@hotmail.com | skype: adam_j_bradley | w:http://www.identityconcepts.com.au | “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait till oil and coal run out before we tackle that.” [ Thomas Alva Edison ]
