Hi,

I will probably also post this to the Postfix mailing list but it is fundamentally an (Open)LDAP question so here goes:

Short version: What is a recommended way to set up virtual mail hosting based on OpenLDAP? I.e. providing mail and authentication services, like SMTP and IMAP, using Postfix and Dovecot, for multiple *independent domains* such as example.net, example.org, example.com?

I am looking for RTFMs, HOWTOs, blogs, or any experience and anecdotes users on this list can provide. I myself no experience designing a DIT in LDAP (I am more at home in Postgres) and have much learning to do.

Long version: I know such setups exist and I have found many references in the archives of this list but there was never a completely straigt- forward answer that didn't say "it depends on your requirements" or involve frontends/add-ons like Jamm or Phamm, which I have no interest in.

So the requirements are basically: * Independent domains and users, i.e. john.doe@example.org is completely different/distinct from john.doe@example.net, even though both may be the same physical human being. * Thus accounts in different domains must have separate passwords fields * Groups and aliases must be possible * Performance should not be terrible, obviously * Applications such as Apache, Ejabberd, Wikis and Webmail clients (to name a few) which support LDAP authentication should be able to query the DIT or DITs without needing any hacks or ugly constructs (this is a vague requirement, I know).

Now I believe the question basically boils down to this:

Should we use multiple independent backend databases (DITs) or one large "hosting" database as described in [1,2]? Which of the two is the better approach? Which is more flexible, which has less administrative or functional overhead?

If we use multiple DITs we probably will have to glue them together somehow, won't we? How would queries against multiple independent DITs look?

Our current setup is more like [1,2], one big hosting database. It is a PostgreSQL database with a few tables for virtual domains (virtual_mailbox_domains in Postfix), virtual users (virtual_mailbox_maps), virtual aliases (virtual_alias_maps) and a few others. It is based loosely on [3].

This works fine but now the need has arisen to see if we can migrate that setup to an LDAP-based one, mainly for flexibility and compatibility with various authentication needs: many applications and services provide some kind of LDAP-based authentication but are hopelessly overwhelmed with SQL backends, especially when the queries are a bit complex.

Thanks in advance!

Andreas

PS: I gathered much from the article in [1] but by now it is over 7 years old and many things have changed so I can't follow it to the letter.

[1] http://www.linuxjournal.com/article/5917 [2] http://www.linuxjournal.com/files/linuxjournal.com/linuxjournal/articles/059... [3] http://workaround.org/ispmail/lenny