cayambelibre.com in one server and listas.cayambelibre.com is in ISP config server. Both MX are configured correctly and the mailing list was working on the same server before I installed ISPconfig.
Just to refresh on of the previous post in this thread. I use to have mailman for testing on this same server before using ISPconfig and it was working ok. Then I insatlled ISP config, I purged mailman and installed again. I suspect something was left on and maybe it was not completly purged. How can I uninstall completly mailman and then configure it with ispconfig. I see no one else is having this issue so maybe it was something left between this to installs.