Is this mandatory. Can I not use the existing root user that I created already on the master mail server that I create several weeks ago? or does this cause issues setting up a second server to talk to master server? Would you recommend to have the second server on a separate public/static IP address. I have a range of 16 public IP addresses and my master mail working server is on one of the those IP addresses and not sure if ISPConfig can mirror on same public IP or best to be on another public IP. Harvey Sharman
You should create a root-user for each server. If one server gets hacked, this will not affect your full setup as the password for the root-user on your master-server is not stored. I use public-ips for all servers
Thank you @florian030 I think I may see problems because master server and second server have different hostnames e.g. vps001.domain.ltd and vps002.domain.ltd. On Microsoft Outlook, the incoming/outgoing mail server on clients computers has the master servers hostname vps001.domain.ltd so if this server has a power failure or has to be rebooted, Microsoft Outlook is not going to connect. I also have trusted SSL certificate CA from Comodo on the master server and second server won't have this SSL certificate installed. I suppose I have to point the master hostname on my providers DNS A records to the second server?? Also to let you know, I have the Barracuda Mail Security that gives me 2 MX servers to clean the emails before Barracuda sends them to my master mail hostname . Barracuda lets me add several mail servers to send the mail. This could be effective. Just let you know, my server is not used for web server, DNS, NS, databases but just only mail accounts and has Roundcube. Thanks, Harvey
You can configure postfix with the same hostname in the main.cf and override the hostname for smtp in the master.cf.
What about the incoming mail through Dovecot on the master hostname vps001.domain.ltd. If the main server went offline for any reason, the incoming mail on Outlook is going to come up with an error that it 'cannot find the POP/IMAP server'? Starting to guest here. Wonder if it is going to be more simpler to just create another mail server completely identical with same master hostname and create same email accounts and passwords as a backup so I can just switch over the hardware including the hard disk drives? Harvey
You must add both servers to your dns and update your dns if one server is down - our use a failover-ip
