I believe that a new and complete guide is needed. I followed ABC of the manual, i shop the manual (Last edited 2016-09-27) but is for Debian 8 (Jessie). ... Does not work! Change Let'Encrypt, PHP etc... I think that many people are like me in difficulty! Can you have an updated guide? Thenks. Best regards.
The tutorial site here already have the latest version of how to build a perfect server for Debian 9. You just need to do some research and have some basic skills and understanding on how to modify accordingly.
As @ahrasis mentioned, a multiserver is just the perfect server guide split to multiple servers, so all you need to know is already in the Debian 9 perfect server guide which you can find here. Nonetheless, we will publish that guide split up for multiple servers in the next version of the manual as well.
Thanks @till and @ahrasis. the problem I found is "Adjust the Server Settings In ISPConfig". On server master stay the quee jobs. ...it almost does not communicate with others. Thanks.
my error is in copy&paste IP! But in the guide of multi-server is missing setting for webmail. I'have download and setting in the web server...
The Perfect Server Guide for Debian Stretch does have webmail setup: https://www.howtoforge.com/tutorial...ovecot-ispconfig-3-1/3/#-installnbsproundcube