Include a mail subdomain

src/freedombone-base-email

     echo "dc_eximconfig_configtype='internet'" > /etc/exim4/update-exim4.conf.conf
     if [[ $ONION_ONLY == "no" ]]; then
         # both ICANN and onion domains
-        echo "dc_other_hostnames='${DEFAULT_DOMAIN_NAME};${EMAIL_ONION_HOSTNAME}'" >> /etc/exim4/update-exim4.conf.conf
+        echo "dc_other_hostnames='${DEFAULT_DOMAIN_NAME};mail.${DEFAULT_DOMAIN_NAME};${EMAIL_ONION_HOSTNAME}'" >> /etc/exim4/update-exim4.conf.conf
     else
         echo "dc_other_hostnames='${EMAIL_ONION_HOSTNAME}'" >> /etc/exim4/update-exim4.conf.conf
     fi
     sed -i 's|pam_mail.so nopen|pam_mail.so dir=~/Maildir nopen|g' /etc/pam.d/su
 
     echo "dc_eximconfig_configtype='internet'" > /etc/exim4/update-exim4.conf.conf
-    echo "dc_other_hostnames='${DEFAULT_DOMAIN_NAME}'" >> /etc/exim4/update-exim4.conf.conf
+    echo "dc_other_hostnames='${DEFAULT_DOMAIN_NAME};mail.${DEFAULT_DOMAIN_NAME}'" >> /etc/exim4/update-exim4.conf.conf
     echo "dc_local_interfaces=''" >> /etc/exim4/update-exim4.conf.conf
     echo "dc_readhost=''" >> /etc/exim4/update-exim4.conf.conf
     echo "dc_relay_domains=''" >> /etc/exim4/update-exim4.conf.conf