LMTP: Undelivered Mail Returned to Sender: User doesn't exist! :-(

[Aki Tuomi]

> On 17 March 2019 13:14 Marek Kozlowski via dovecot <dovecot at dovecot.org> wrote:
> 
>  
> :-)
> 
> I'm using postfix for mail delivery and dovecot for mailbox access imaps 
> pop3s.
> 
> Postfix resolves, verifies and overwrites users' addresses by numerous 
> subtle LDAP queries. However users are visible as local ones (openldap, 
> pam, nss) in the sense I can run `id' or `finger' queries and receive 
> replies.
> 
> Dovecot handles all mailboxes over imap/pop correctly with no additional 
> configuration for LDAP. Just (10-mail.conf):
> 	
> mail_location = maildir:/mailboxes/%u
> 
> and it works fine.
> 
> Because I'd like to use pigeonhole I'm trying to make local delivery via 
> dovecot LMTP (https://wiki2.dovecot.org/HowTo/PostfixDovecotLMTP). I've 
> configured the socket and added to `/etc/postfix/main.cf' the line:
> 
> mailbox_transport = lmtp:unix:/var/spool/postfix/private/dovecot-lmtp
> 
> I think that id dovecot handles mailboxes correctly over imap/pop it can 
> easily find the users and their mailboxes so it doesn't need any 
> additional configuration for LDAP. Unfortunately it doesn't work and 
> results in:
> 
> Undelivered Mail Returned to Sender: User doesn't exist! :-(
> 
> What's the thing I've missed?
> 
> Best regards,
> Marek

If your usernames do not have a domain, you need to configure auth to lookup users by local part only.

Depending a bit on situation, sometimes it's better to do

auth_username_format = %Ln

sometimes it's better to configure the passdb itself.

Aki