I tried to use dovcots lmtp instead of dovecot-lda. postfix has in master.cf ... dovecot-lda -f ... -d ${user} to separate the user part from user@hostname.domain. So lookup of "user" succeeds in userdb (LDAP) done by dovecot-lda.
I have always local addresses like to=<user@hostname.domain> postfix/lmtp[6579]: [ID 197553 mail.info] B3CDA66A16: to=<h0094slk@mailstore4.hu-berlin.de>
With lmtp the userpart must be separated also. I tried user_filter (LDAP) with %n, %Ln, %8n without success: userdb lookup: user@hostname.domain doesn't exist)
dovecot-2.1.17 I used "doveadm user h0094slk" and "doveadm user h0094slk@mailstore4.hu-berlin.de" for my tests.
userdb { driver = ldap args = /usr/dovecot/etc/ldapuser.conf } and ldapuser.conf with ... user_filter = (&(uid=%n) (objectClass=cmsAccount)) user_attrs = homeDirectory=home
I modified user_filter like uid=%Ln or uid=%8u
success for doveadm user h0094slk (because nothing to split) userdb: h0094slk home : /home/p0094/h0094slk
but no success for doveadm user h0094slk@mailstore4.hu-berlin.de userdb lookup: user h0094slk@mailstore4.hu-berlin.de doesn't exist
It looks for me like user_filter do not use variables at this point? What I'm missing?
-- Mit freundlichen Grüßen --- Burckhard Schmidt
Abteilung Systemsoftware und Kommunikation ZE Computer- und Medienservice der Humboldt-Universität zu Berlin Postanschrift: Unter den Linden 6, 10099 Berlin Standort: Rudower Chaussee 26; 12489 Berlin Tel.: +49-30-2093-70058 Fax: +49-30-2093-2959 Mail: bschmidt@cms.hu-berlin.de