[Evolution] New mailing list reminder

[Patrick O'Callaghan <poc usb ve>]

This is just a head's up that the new list is now available for
subscription, see:

https://mail.gnome.org/archives/evolution-list/2022-November/msg00181.html

We've had some sign-ups in the last day or so but most people still
haven't bothered. It's important to know that when this (OLD) list is
shut down, it could happen without warning. It's not under our control,
and we've been told that once it happens any posts here will simply
bounce. Of course if we get an update on this we will post it.

Due to the uncertainty, I'm going enable posting to the NEW list as of
now. Once again, please do *not* cross-post to both lists.

poc