I want to send an email from a Linux Shell script. What is the standard command to do this and do I need to set up any special server names?
If both exim and ssmtp are running, you may enter into troubles. So if you just want to run a simple MTA, just to have a simple smtp client to send email notifications for insistance, you shall purge the eventually preinstalled MTA like exim or postfix first and reinstall ssmtp.
Then it's quite straight forward, configuring only 2 files (revaliases and ssmtp.conf) - See ssmtp doc - , and usage in your bash or bourne script is like :
#!/bin/sh
SUBJECT=$1
RECEIVER=$2
TEXT=$3
SERVER_NAME=$HOSTNAME
SENDER=$(whoami)
USER="noreply"
[[ -z $1 ]] && SUBJECT="Notification from $SENDER on server $SERVER_NAME"
[[ -z $2 ]] && RECEIVER="another_configured_email_address"
[[ -z $3 ]] && TEXT="no text content"
MAIL_TXT="Subject: $SUBJECT\nFrom: $SENDER\nTo: $RECEIVER\n\n$TEXT"
echo -e $MAIL_TXT | sendmail -t
exit $?
Obviously do not forget to open your firewall output to the smtp port (25).