[Users] mailing list

[mi]

Ernie,

While i support the idea of using claws templates ... but doesn't your situation sound like you want to create your own mailing list ? Considering that if someone wants to answer to everyone, they might not use an able mailer like claws and maybe it doesn't work out-of-the box for them.
With single mails, won't work anyway.

I didn't try or look into anyone here but you can find hints to 'free list' providers online:

 https://www.uplead.com/free-email-lists
 https://www.leadsplease.com/email-lists/free

and there are probably many more choices.

Another way to keep in contact and updatet would be creating a publicly (as in: public to the invited) open document in Google Docs or Owncloud or Nextcloud and the like.

I've worked with Nextcloud so far but AFAIK somebody needs to run an instance on their server. Some folks get it for free included in their homepage plan though.
I won't recommend dropbox and facebook for personal disinclination but YMMV. The way it works with Nextcloud is, you send a link by email which opens a simple document. More like a textfile. Any typing will be immediately updatet, by the word. Dunno how it deals with concurrent access though.