[Dovecot] configuring sendmail to work with dovecot+LDAP

[Andrzej Adam Filip]

Douglas Maus <dmaus at speakeasy.net> wrote:
> I would like to setup dovecot (1.1.20) with LDAP virtual users,
> but I don't seem to understand how to get my sendmail to accept
> mail for the virtual users.
> (I am rather new to this, so I may have some misunderstandings)
>
> I have followed - wiki.dovecot.org/HowTo/DovecotOpenLdap
> (OpenLDAP 2.3.43)
> and I think I have IMAP working for virtual users.
> I can connect to port 143, enter a username and password and
> it works.
>
> Now I surmise I need to configure my SMTP server to accept mail
> for these LDAP virtual users, and deliver it appropriately.
> (The above HowTo doesn't address this step, from what I can tell)
>
> I read - wiki.dovecot.org/LDA and wiki.dovecot.org/LDA/Sendmail
> (I'm using OpenBSD 4.7, which uses sendmail for MTA / SMTP server,
> sendmail version 8.14.3)
>
> For sendmail.cf, I made the changes in my sendmail.mc file to include the
> dovecot mailer (calling /usr/local/libexec/dovecot/deliver),
> and compiled with m4 and installed the new sendmail.cf
> [....]
> When I try to test this, (telnet www.example.org 25)
> If I try: MAIL TO:jdoe at www.example.org
>  I get "User unknown"
> I see that if I try: MAIL TO:jdoe at example.org
>  I get "Relaying denied"
> Either way it doesn't get delivered.
>
> Thank you for any help.
> And if anyone knows a good basic tutorial for dovecot+LDAP+sendmail
> I would really appreciate it.
> [...]

http://wiki.dovecot.org/LDA/Sendmail tells about adding "per virtual
domain" routing entry into sendmail's mailertable.
[ after it mailertable requires recompilation with makemap ]

IF the virtual domain is a local email domain 
THEN mailertable is not consulted and sendmail (typically) checks
     existence of OS account (no OS account => "User unknown" )
ELSE access (table) entry is required to avoid "Relaying denied"

# access (table) entry to allow accepting messages to the.virtual.domain
# from anywhere
to:the.virtual.domain RELAY

To get list of local email domains as root execute
  echo '$=w' | sendmail -bt
To stop sendmail from guessing list of local email domain you may use
define(`confDONT_PROBE_INTERFACES',`True') in sendmail.mc
  http://www.sendmail.org/m4/tweaking_config.html#confDONT_PROBE_INTERFACES

*WARNINGS* The above:
a) WILL NOT configure SMTP AUTH to use LDAP
   [ AFAIK sendmail supports Cyrus SASL only ]
b) WILL NOT make sendmail check existence of virtual mailbox in reply to
   "RCPT TO:" in SMTP session
"a" and "b" require another configuration

-- 
[pl>en: Andrew] Andrzej Adam Filip : anfi at onet.eu
We have lingered long enough on the shores of the Cosmic Ocean.
  -- Carl Sagan