make Postfix -> Dovecot delivery over LMTP (was LDA) (#305) (#360)

target/dovecot/10-master.conf

@@ -47,7 +47,8 @@ service pop3-login {
 
 service lmtp {
   unix_listener lmtp {
-    #mode = 0666
+    mode = 0660
+    group = postfix
   }
 
   # Create inet listener only if you can't use the above UNIX socket

target/dovecot/20-lmtp.conf

@@ -0,0 +1,19 @@
+##
+## LMTP specific settings
+##
+
+# Support proxying to other LMTP/SMTP servers by performing passdb lookups.
+#lmtp_proxy = no
+
+# When recipient address includes the detail (e.g. user+detail), try to save
+# the mail to the detail mailbox. See also recipient_delimiter and
+# lda_mailbox_autocreate settings.
+#lmtp_save_to_detail_mailbox = no
+
+# Verify quota before replying to RCPT TO. This adds a small overhead.
+#lmtp_rcpt_check_quota = no
+
+protocol lmtp {
+  # Space separated list of plugins to load (default is global mail_plugins).
+  mail_plugins = $mail_plugins sieve
+}