Enable sieve with LMTP.

modoboa_installer/scripts/files/dovecot/conf.d/20-lmtp.conf.tpl

@@ -0,0 +1,17 @@
+##
+## 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
+
+protocol lmtp {
+  postmaster_address = %postmaster_address
+  # Space separated list of plugins to load (default is global mail_plugins).
+  mail_plugins = $mail_plugins sieve
+}