Interesting, thanks. I haven't run email servers since the early 00's. At the time we were running the largest cluster of email servers in the UK for customers like friendsreunited.co.uk and match.com among others. We spanned our RIPE AS number into the US along with half our group of class C's to provide resilience. You weren't supposed to do that. Nobody noticed 😅 It all got very complex after that 😂

Well I am from the age where there was no Internet. Most of my stuff is zero standard by choice. I do not use any service from others. In the early 2000 we have been the first big e-commerce in an EU country with a well structured VPN and remote workers. We used voip when nobody even knew what it was and we essentially created from scratch all our management and picking optimization software. Now by choice I moved to mostly teaching tech stuff and I use only self hosted services. No google or meta allowed inside my property. All the data is ours and not a single picture of me is on the network. I like to keep living without pushy commercials and pay by use apps. Next step will probably be the development of non standard automation over tiny sized agriculture projects.