[Dovecot] Problem switching from Dovecot LDA to LMTP - on dovecot 2.2.4

[Michael Long]

Dovecot LDA has been working fine for me but when I tried to follow the 
wiki and switch to LMTP I get:

Recipient address rejected: User unknown in local recipient table;

In postfix/main.cf I went from:
mailbox_transport = dovecot-spam
to
mailbox_transport = lmtp:unix:private/dovecot-lmtp

Added this:
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
     group = postfix
     mode = 0600
     user = postfix
  }
}

protocol lmtp {
   mail_fsync = optimized
   postmaster_address = postmaster at domainname
   mail_plugins = sieve zlib
}

And some other pertinent parts of the config:

passdb {
   args = /etc/dovecot/passdb
   driver = passwd-file
}
passdb {
   driver = pam
}

protocol lda {
   mail_fsync = optimized
   auth_socket_path = /var/run/dovecot/auth-master
   deliver_log_format = msgid=%m: %$
   mail_plugin_dir = /usr/local/lib/dovecot
   mail_plugins = sieve zlib
   postmaster_address = postmaster
   quota_full_tempfail = yes
   rejection_reason = Your message to <%t> was automatically rejected:%n%r
   lda_mailbox_autocreate = yes
}