It is good idea to get notified when someone logs into your Linux server.
First be sure that your server is able to send email (at least Postfix + valid ptr)
Open /etc/profile and at the bottom add the following:
if [ -n "$SSH_CLIENT" ]; then TEXT="$(date): ssh login to ${USER}@$(hostname -f)" TEXT="$TEXT from $(echo $SSH_CLIENT|awk '{print $1}')" echo $TEXT|mail -s "ssh login $(hostname -f)" EMAIL@DOMAIN.TLD fi |
Replace EMAIL@DOMAIN.TLD with your email
Save file and logout/login again. Check your inbox