ISPConfig Perfect Multiserver setup on Ubuntu 20.04 and Debian 10 - Page 8
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Finalizing your setup
Your setup is now done! In case you want to add another server later on, simply repeat the steps for that server type, and add a MySQL user for it on the master server.
You can support ISPConfig by purchasing our manual: https://www.ispconfig.org/documentation/
The followings links are some useful tutorials/pointers for further setup:
Setting up mail (rDNS, SPF, DKIM): https://www.howtoforge.com/how-to-install-an-email-server-with-ispconfig-on-debian-10/
Setting up autoconfig (automatic configuration for your email clients): https://schaal-it.com/ispconfig-automail/
Doveadm sync (dsync) FAQ: https://www.howtoforge.com/community/threads/dsync-faq.86543/
Improve the security of PHPMyAdmin and the rspamd interface: https://www.howtoforge.com/community/threads/improving-the-security-of-phpmyadmin-and-rspamd-ui.86544/
If you have any questions, ask them on the forum.