ListMonk

https://news.ycombinator.com/item?id=28389346&utm_source=chatgpt.com

This seems to be the highest growth, full A/B testing automation, survivable option. PhPlist offers less survivability. OSE may consider this, with easy install, or choose Mailman 3 without automation for the most survivable option - but the install appears complex.

There are considerations that need to be taken for running on your own server - see 20% down in chat [1] - to prevent blocking by spam filters.