diff --git a/README.md b/README.md
index b6068c91..5a3056e7 100644
--- a/README.md
+++ b/README.md
@@ -137,7 +137,7 @@ Backup database:
 source mailcow.conf
 # Create
 DATE=$(date +"%Y%m%d_%H%M%S")
-docker-compose exec mysql-mailcow mysqldump --default-character-set=utf8 -u${DBUSER} -p${DBPASS} ${DBNAME} > backup_${DBNAME}_${DATE}.sql
+docker-compose exec mysql-mailcow mysqldump --default-character-set=utf8mb4 -u${DBUSER} -p${DBPASS} ${DBNAME} > backup_${DBNAME}_${DATE}.sql
 ```
 
 ### Backup maildir (simple tar):
diff --git a/data/Dockerfiles/data-container-dkim/Dockerfile b/data/Dockerfiles/data-container-dkim/Dockerfile
deleted file mode 100644
index c48a0411..00000000
--- a/data/Dockerfiles/data-container-dkim/Dockerfile
+++ /dev/null
@@ -1,8 +0,0 @@
-FROM debian:jessie
-
-RUN mkdir -p /data/dkim/keys \
-	&& mkdir -p /data/dkim/txt \
-	&& chown -R 33:33 /data/dkim
-VOLUME /data/dkim
-USER www-data
-CMD ["echo", "Data container for dkim keys"]
diff --git a/data/Dockerfiles/data-container-vmail/Dockerfile b/data/Dockerfiles/data-container-vmail/Dockerfile
deleted file mode 100644
index 76f4e41a..00000000
--- a/data/Dockerfiles/data-container-vmail/Dockerfile
+++ /dev/null
@@ -1,10 +0,0 @@
-FROM debian:jessie
-
-RUN groupadd -g 5000 vmail \
-	&& useradd -g vmail -u 5000 vmail -d /var/vmail
-
-RUN mkdir -p /var/vmail \
-  && chown -R 5000:5000 /var/vmail
-VOLUME /var/vmail
-USER vmail
-CMD ["echo", "Data container for mail"]