License

README.md

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 [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=JWBSYHF4SMC68)
 
 Please see [the official documentation](https://mailcow.github.io/mailcow-dockerized-docs/) for instructions.
+
+**Important**: mailcow makes use of various open-source software. Please assure you agree with their license before using mailcow.
+Any part of mailcow itself is released under **GNU General Public License, Version 3**.