I’m not entirely sure what you are asking for.
Yes, you can setup a chain of SMTP servers which will redirect email’s however you like. Postfix is an excellent choice for this.
If you want emails sent to reflector@example.com to be automatically forwarded to many people you can do that with the /etc/aliases
file which most SMTP servers provide.
If you are wanting a more complete system (for example to allow people to subscribe to the email address, to automatically unsubscribe bouncing addresses, to create archives, to only allow some people to send messages etc) you want to use a mailing list.
If this is for group discussion you want something like Mailman. If this is for newsletters (eg. only you send messages), you might look at something like ListMonk or Mautic.
As far as I know, this doesn’t exist yet in the open source / selfhostable world. Lots of people want it though and some are starting to cobble together systems that work for them.
https://lemmy.world/post/2048481