Tiny application written in Go that checks if your external Internet IP has changed. Sends an e-mail to inform you about your new IP address.
Uses www.ipify.org to lookup the IP address.
go install github.com/fdebrabander/dyn-ip-mailer
Copy the example configuration file .dyn-ip-mailer.yaml to $HOME, then configure the correct SMTP settings.
Add an entry to the cron with crontab -e to periodically check if your IP changed. Please be nice to ipify.org! Replace 17 with some random minute.
17 */4 * * * dyn-ip-mailer > /dev/null 2>> $HOME/.dyn-ip-errors