On Thu, Jun 28, 2012 at 07:00:18AM -0400, James B. Byrne wrote: > On Thu, June 28, 2012 06:36, James B. Byrne wrote: > > Perhaps this would be clearer to me if you would be so kind as > > to give me the canonical use cases for virtual_aliases and for > > virtual_domains > > This should read "virtual_mailbox_domains"
Likewise there is no "virtual_aliases" setting. I don't think there is anything better than the Address Class README to answer that question. You have, as admin, choices to make. Right and wrong choices are not really possible, but there are better and worse choices depending upon your situation. Virtual(5) aliasing of addresses to virtual(8) mailboxes introduces another layer of complexity without benefit. Aforementioned README recommends using virtual_alias_domains for final delivery to system accounts, using local(8). What this does is to correct the shortcoming of $mydestination, whereby all system users and aliases(5) exist in all $mydestination domains. Sometimes (often) sites will want namespace separation, so that b...@example.com is not necessarily the same as b...@example.net. The choice of local(8) vs. virtual(8) mailbox delivery is not as simple as it may seem. Each choice tends to present different security issues for a site. It might help to understand that the virtual delivery agent began as a clone of local with some of the features removed. Therefore, virtual(5) aliasing gives you the namespace separation while retaining the features removed from the virtual(8) delivery agent. Users can maintain .forward files, deliver mail to commands, et c. > > insofar as Postfix considers them. Why is the latter superior > > to the former in my situation? I can't speak for Noel and his reasoning in recommending it (but I can echo his comments about peer review on the list.) In my view, virtual mailboxes can be easier to implement in situations with external delivery agents. Not having closely followed the whole thread, I hope I have not confused matters further, but I thought I saw something about Cyrus IMAP upthread? That's an external (non-Postfix) delivery agent. -- http://rob0.nodns4.us/ -- system administration and consulting Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:
