I must admit that I'am getting out of ideas slowly, maybe you should consider to do a clean reinstall.
netstat -tanp|grep master or netstat -tanp|grep 1002 just to ensure, that your postfix is listening on the right ports. If you run a clean install, better use an os that is easier to maintain (debian or ubuntu).
The short hostname is an IP address which is why that instruction was slightly confusing but you were right that it does not affect the problem.
So would the above output confirm that the ports are open or could they still be blocked? Are there any other tests I should run? I'm just checking with the server provider to see if they block those ports for any reason.
I can Telnet the port from localhost, but not from remote. However, the error message indicated a localhost refusal... Code: amavis[2399]: (02399-01) Blocked MTA-BLOCKED {TempFailedOpenRelay}, [127.0.0.1] Code: Temporary MTA failure on relaying, from MTA(smtp:[127.0.0.1]:10025): 451 4.3.0 Error: queue file write error (in reply to end of DATA command))
Could you provide the full output from netstat? Did you set the hostname in amavis? Is postfix listen on 127.0.0.1 to all ports?
We don't appear to be making any progress with this port issue. I installed a different email server instead, as a test, and it worked perfectly straight out the box. Maybe the (CentOS 7) guide might need some attention, who knows. However, I am very keen to use Ispconfig, I still have faith in the product, so I'm going to take your advice and try installing on a different OS. A friend has advised I try Debian, so I'll give that a go. I noted from previous posts, here and elsewhere, that the (MTA relay) problem I had was fixable with a correction to the db username/password, otherwise it remained mostly unresolved. Obviously this is not an ispconfig issue, but as part of the overall setup it would of course have been useful to determine.
I install several servers a week with different OS (CentOS, Debian and Ubuntu) and I use the perfect server guides and the systems work out of the box. Neither problems with the centos setup nor I had to modufy anything regarding relaying. Debian is faster and easier to install btw, that's why it is recommended for ISPConfig here in the forum and at ispconfig.org.
As an experienced Linux user and frequent installer, I doubt you actually follow the guides. They are probably there as little more than a reference and I doubt they get much more than a sideways glance. It isn't quite so straight forward for someone who has never used something like this before, where some more detailed explanation might be useful, or at some point, even necessary. Nonetheless, I appreciate your help and I'm optimistic that an alternative approach will be successful in my particular case.
What I actually do is to just copy/paste the commands blindly without reading the text parts of the guide, so when a blind copy/paste of the guide results in a working setup then the tutorials should be ok in my opinion. I tested the guides here in the office with a person that never used Linux before, I just told him to copy/paste each command that is marked as command to the server shell that I opened for him and the setup worked out of the box, so maybe I should just remove all explanations from the guides. Most problems with the setups occur when the base system is not clean (some providers provide minimal setups which are highly customized and therefore very different from a standard minimal setup of the same OS) or that a step of the tutorials is left out or modified as the user thought that the guide must be wrong.
.. that's kinda what I meant. There are parts of the guide which are not commands, and can't copied and pasted. You can remove the explanations if you think being less helpful is a solution. Of course people are going to use this with different setups. That is exactly why more detailed explanations would be helpful. If I was experienced, and familiar with the process, I would be happy to offer to make a setup video for you. Videos often contain seemingly random commentary that can be incredibly helpful. I didn't say my problem was caused by your setup guide.