email: minor fixes

- Add sudo package
- Add 25MB message limit
- Switch getmail to Maildir
- Fix startup script

images/email/Dockerfile

   apt-get -y install --no-install-recommends \
   rsyslog \
   postfix postfix-pcre postfix-ldap \
-  cron getmail4 \
+  sudo cron getmail4 \
   mutt swaks \
   dovecot-core dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-ldap \
   libsasl2-2 sasl2-bin libsasl2-modules-ldap

images/email/config/postfix/main.cf

     localhost.$mydomain
     localhost
 
+# 25 MB
+message_size_limit = 26214400
 
 ###################################################################################################
 ### Virtual Transport ###

images/email/getmail/template.getmailrc-example

 # delete_after = 10 # days
 
 [destination]
-type = MDA_external
-path = /usr/sbin/sendmail
-arguments = ("-i", "-bm", "your-user@your-domain.com")
-unixfrom = true
+#type = MDA_external
+#path = /usr/sbin/sendmail
+#arguments = ("-i", "-bm", "your-user@your-domain.com")
+#unixfrom = true
+# or
+type = Maildir
+path = /srv/vmail/your-user@your-domain.com/Maildir/.Gmail/ # or any other Maildir folder
+user = vmail

images/email/startup.sh

-#!bin/bash
+#!/bin/bash
 
 # set LDAP password from secret
 if [ ! -z $LDAP_BIND_PWD_FILE -a -f $LDAP_BIND_PWD_FILE ]; then