Remove /data volume

Signed-off-by: René Jochum <rene@jochum.dev>

Dockerfile

@@ -12,6 +12,6 @@ COPY start.py /start.py
 
 EXPOSE 25/tcp 465/tcp 587/tcp
 
-VOLUME ["/data", "/overrides", "/cert"]
+VOLUME ["/overrides", "/cert"]
 
 CMD /start.py

start.py

@@ -46,11 +46,6 @@ if os.path.exists("/overrides/postfix.master"):
         if is_valid_postconf_line(line):
             os.system('postconf -Me "{}"'.format(line))
 
-os.system("/bin/mkdir -p /data/vmail")
-os.system("/bin/chmod u=rwX,g=rX,o=rX /data")
-os.system("/bin/chown -R mail: /data/vmail")
-os.system("/bin/chmod -R u=rwX,g=rX,o= /data/vmail")
-
 os.system("/usr/libexec/postfix/post-install meta_directory=/etc/postfix create-missing")
 # Before starting postfix, we need to check permissions on /queue
 # in the event that postfix,postdrop id have changed