Fwd: Mail delivery failed: returning message to sender

And...

> Begin forwarded message:
> 
> From: Mail Delivery System <Mailer-Daemon@openlinksw.com>
> Subject: Mail delivery failed: returning message to sender
> Date: March 24, 2022 at 02:37:01 PM EDT
> To: tthibodeau@openlinksw.com
> 
> This message was created automatically by mail delivery software.
> 
> A message that you sent could not be delivered to one or more of its
> recipients. This is a permanent error. The following address(es) failed:
> 
>  sds-wg@dif.groups.io
>    host lb01.groups.io [45.79.81.153]
>    SMTP error from remote mail server after end of data:
>    510 5.1.1 Your email address, tthibodeau@openlinksw.com, is not subscribed to that group. To subscribe, send an email to sds-wg+subscribe@groups.io, or visit https://groups.io/g/sds-wg
> Reporting-MTA: dns; mail.openlinksw.com
> 
> Action: failed
> Final-Recipient: rfc822;sds-wg@dif.groups.io
> Status: 5.0.0
> Remote-MTA: dns; lb01.groups.io
> Diagnostic-Code: smtp; 510 5.1.1 Your email address, tthibodeau@openlinksw.com, is not subscribed to that group. To subscribe, send an email to sds-wg+subscribe@groups.io, or visit https://groups.io/g/sds-wg


(My previous message CCed that list but didn't get there.
This message doesn't CC that list, nor does it fully quote my 
previous message.  I leave the immediate decision of how to 
handle raising my concerns to DIF, to Dmitri & CCG chairs.)

I'm pretty sure that subscription to the sds-wg list is 
(or is meant to be) restricted to DIF members, just like 
substantive participation in this "joint" project.

I can only be *pretty* sure, because the web page the error
above points to -- <https://groups.io/g/sds-wg> -- just says,
"Sorry, but that group does not exist."  Most helpful!

It appears that adding a subdomain to the URI -- making it
<https://dif.groups.io/g/sds-wg> -- takes me to the intended
destination -- <https://lists.identity.foundation/g/sds-wg>.

But the information there is rather bare-bones and while it
does provide some information about how individuals and
organizations can join DIF, it does not make clear what 
costs or obligations are entailed thereby, particularly 
where these differ from those associated with W3C membership.

Be seeing you,

Ted