diff --git a/Dockerfile b/Dockerfile
index 0176e4e..19cbb39 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,4 @@
+# Based on official Dockerfile: https://github.com/dovecot/docker
 FROM alpine:3
 
 LABEL org.opencontainers.image.authors="markus@birth-online.de"
@@ -5,6 +6,8 @@ LABEL org.opencontainers.image.authors="markus@birth-online.de"
 ENV container=docker \
     LC_ALL=C
 
+ARG username=vmail
+
 RUN apk add --no-cache \
   tini \
   dovecot \
@@ -21,9 +24,9 @@ RUN apk add --no-cache \
   mkdir /conf && \
   echo "!include_try /conf/*.conf" >> /etc/dovecot/dovecot.conf && \
   mkdir /data && \
-  addgroup -g 1000 vmail && \
-  adduser -h /data -u 1000 -D -G vmail vmail && \
-  chown vmail:vmail /data
+  addgroup -g 1000 $username && \
+  adduser -h /data -u 1000 -D -G $username $username && \
+  chown 1000:1000 /data
 
 COPY local.conf /conf/local.conf
 
diff --git a/local.conf b/local.conf
index 9c1a08d..8cfd218 100644
--- a/local.conf
+++ b/local.conf
@@ -1,4 +1,4 @@
-## You should mount /etc/dovecot if you want to
+## You should mount /conf if you want to
 ## manage this file
 
 mail_home=/data/%Lu