echo "Test text" | mail -s "Test Mail" me2@gmail.com

send-mail: Cannot open mail.google.com:587

send-mail: Server didn't like our AUTH LOGIN (530 5.7.0 Must issue a STARTTLS command first. ml2sm3592928igb.10 - gsmtp)

#
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
# root=postmaster

# The place where the mail goes. The actual machine name is required no
# MX records are consulted. Commonly mailhosts are named mail.domain.com
# mailhub=mail

# Where will the mail seem to come from?
#rewriteDomain=

# The full hostname
hostname=raspberrypi

# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
FromLineOverride=YES


root=me@gmail.com
mailhub=smtp.gmail.com:587
AuthUser=me@gmail.com
AuthPass=mypass
UseSTARTTLS=YES

# sSMTP aliases
#
# Format:   local_account:outgoing_address:mailhub
#
# Example: root:your_login@your.domain:mailhub.your.domain[:port]
# where [:port] is an optional port number that defaults to 25.

root:me@gmail.com:mail.google.com:587

sudo apt-get update
sudo apt-get install ssmtp

root=rpi3abc@gmail
mailhub=smtp.gmail.com:465
FromLineOverride=YES
AuthUser=rpi3abc@gmail.com
AuthPass=testing123
UseTLS=YES

apt-get update
sudo apt-get install mpack