diff --git a/files/Dockerfile b/files/Dockerfile
index 6793aae..c1668e7 100644
--- a/files/Dockerfile
+++ b/files/Dockerfile
@@ -18,6 +18,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
      dovecot-imapd \
      dovecot-ldap \
      dovecot-sieve \
+     dovecot-submissiond \
      dovecot-managesieved \
      dovecot-antispam \
      bogofilter \