What I think is happening is that because I enabled email on Server A, Server A is automatically looking for that user's email inbox to drop the email as opposed to routing it though the internet where is would use the MX records listed in the DNS.
So the question becomes how do you log into an email server without enabling inbound email.
I did some tests and they way it is configured now I can email anyone other than <user>@DomainB.com and if I disable "Incoming Email" then the server A user "relay@serverB.com" cannot authenticate for the purpose of sending emails.
Agreed, this would be very useful. Would love to be able to assign specific IP addresses to specific domains.
It would also be nice to be able to disable the "You are seeing this page because the DNS record of nn.nn.nn.nnn is set to this server's IP but Cloudron has no app configured for this domain." for http requests sent directly to the server IP.
Zabbix is running on a Master Node and each Client has an Agent. (Yes the master is an external System)
Zabbix can monitor clients active and passive.
Passive means the Master asks the system for data and the system delivers.
This does not always work within special networks where the master can not reach the client.
Then you use active monitoring then the client reports all data in a certain interval to the master.
There can be a master / slave / proxy setup for big scale monitoring solutions. (Google Zabbix HA Cluster Setup for more details)
Maybe the Cloudron app needs to generate its own partition to run from, where regular app storage can't saturate the OS or Cloudron partitions?
Right. The main issue, it's not possible to create proper disk partitions in VPS 😕 i.e one can only create file backed loop back file systems but such things are not to be used in production and I have no idea about their reliability/durability.