Setting up Heirloom MailX to send emails from linux(Debian/ ubuntu) system:

Heirloom_MailX.sh

mkdir MailX
cd MailX
#Download file
wget  http://ftp.debian.org/debian/pool/main/h/heirloom-mailx/heirloom-mailx_12.5.orig.tar.gz
 
#Download patch
wget http://www.linuxfromscratch.org/patches/blfs/svn/heirloom-mailx-12.5-fixes-1.patch
 
#unZip
tar -xvzf heirloom-mailx_12.5.orig.tar.gz
 
#Remove after unzipping
rm -rf heirloom-mailx_12.5.orig.tar.gz
 
#Run following commands
patch -Np1 -i ../heirloom-mailx-12.5-fixes-1.patch &&
make SENDMAIL=/usr/sbin/sendmail -j1
 
#as a sudo user
make PREFIX=/usr UCBINSTALL=/usr/bin/install install &&
ln -v -sf mailx /usr/bin/mail &&
ln -v -sf mailx /usr/bin/nail &&
install -v -m755 -d /usr/share/doc/heirloom-mailx-12.5 &&
install -v -m644 README /usr/share/doc/heirloom-mailx-12.5
 
#Append config file with BC smtp
    cat >> /etc/nail.rc <<EOF
    # set smtp=smtp://smtp.server.tld:port_number
    set smtp=smtp://smtp.emailsrvr.com
    # tell mailx that it needs to authorise
    set smtp-auth=login
    # set the user for SMTP
    set smtp-auth-user=bcsrvr@bluecava.com
    # set the password for authorisation
    set smtp-auth-password=RedSky123
    EOF
     
# Test MailX by sending a mail
echo "hello world" | mail -s "a subject" sumeet@qualia-media.com   

memory.sh

#!/bin/bash
while true
do
 [ $(free -m| grep  Mem | awk '{ print int($3/$2*100) }') -gt "85" ] && echo "Memory used is more than 85% - GraphDB - SandBox " | mail -s "Memory used more than 85%" devops@bluecava.com || echo "Memory used less than 85%"
 sleep 600
done

monitor_port.sh

#!/bin/bash
 
while true
do
if lsof -Pi :3000 -sTCP:LISTEN -t >/dev/null ; then
    echo "Aerospike Running"
else
    echo "Aerospike PORT DOWN!!!: 3000 GraphDB" | mail -s "Aerospike PORT DOWN!!!: 3000 GraphDB"
fi
sleep 120
done

Hi,
I have just installed mailx on Ubuntu 16.04 , in which directory can i find the configuration file to set the SMTP server and password?