sendmail+openldap+multihosting

[Maximiliano Kolus <mkolus@tlh.com.ar>]

Hello!

        We're trying (i hope before we grow old or our boss kill us :) ) to
achieve this configuration:

* Mail multi-hosting (several domains on the same phisycal machine)
* Each domain will have it's own user space. Each IP alias will appear as a
different domain on the SMTP and POP-3 port. I mean: user jdoe on
mail.domain1.com will be completely different to jdoe on mail.domain2.com.

        The POP-3 server is not the problem (in fact, we're making one from
scratch), but sendmail and mda configuration is.

        Both of us are a little more than beginners on the sendmail world and we
almost ate ('read' in other way of speaking :) ) the O'Reilly book.

        From what we researched, we found this possible approarch:

* Modify sendmail.cf so it will deliver the target domain to the local MDA.
* Modify the local MDA. Since it knows the destination domain, it will
deliver mail to the appropiate spool directory for each domain (IE:
/var/spool/mail/domain1/jdoe)
* The part left to the POP-3 server is simple: it will authenticate the
user knowing wich server him/her is connected to. Each domain will have
it's own user space. Much like cucipop does.

        Where does openldap fit in this mess?. Well, we wish to use in for two
things:

* Sendmail will lookup users in the LDAP servers, he will know -trough it-
if a user exists or not.

* The POP-3 server will authenticate users using the LDAP server.

        Where are we stuck?. The organization we find appropiate for this mail
configuration was:

o=Amtec
        ou=MailHost
        ou=Domain1
                cn=jdoe
                        maildrop=jdoe@domain1.com
                        userpassword=you_will_never_hack_this_pass
                cn=webmaster
                        maildrop=webmaster@domain2.com
                        userpassword=apache-rules!
        ou=Domain2
                cn=jdoe
                        maildrop=jdoe@domain1.com
                        userpassword=secret

        As you can see, the domains are on different tree branchs. We didnt figure -yet- the way of telling sendmail to search users of domain1 in branch 1 and domain2. The K configuration command of sendmail, apparently, dont allow us to tell where to start the search for each domain.

        How you can help?. We need guidelines to accomplish this configuration (multiple mail servers for different domains on the same machine). If any of you did this or have some ideas to share, it will help us a lot. Im not asking for a solution to this (it will be better, of course), just ideas on how to accomplish this.

Maximiliano Kolus
Webmaster/Programmer
http://www.tlh.com.ar
ICQ: 21902432
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