I am using old eudora and it works well ... and also no more

I have a dedicated machine with low-traffic citizen research-oriented 300 wiki farm. So many mail addresses and a reasonable mailman use, that I coordinated through an MQ-like management plugin I wrote, nearly 20 years ago. After a CentOS upgrade, my hosting provider has transferred my config to a new machine. Then my outbound mail traffic was blocked - on every account. I tweaked the security parameters of WHM and told my provider to refuse all the outbound traffic which did not come from my CyberGhost dedicated IP. And all a sudden, one account started working. The idea was then to try to understand why that mail address had a different behavior (same Exim host, etc.). I thought I could only get a table of all the cPanel parameters from my different sites. But there I am lost. I do not know where to find it or the way cPanel is built, if there is a way to get or build an "excel" table of all the sites parameters? Thank you for your help!