I found it strange that this error message didn't contain info on the message I tried to post (which I sent from the wrong address)
Also, I'm wondering if "no longer a member of the group" is our default text or whether this is showing because I was once a member of the group.
Matt, you received the "no longer a member of the group" email because you mentioned that you used a different email address to compose the email than the email address registered on the Commons and is a member of that group.
Secondly, the email address you used to post the group topic appears to have an account on the Commons (probably is from a secondary test account). Does that sound about right? I don't have enough debug info to find out which user account that is though. If the email address did not exist in the system, you would have received a "user does not exist" email that resembles this:
https://github.com/r-a-y/bp-reply-by-email/blob/master/includes/bp-rbe-functions.php#L1011
However, the "no longer a member of the group" error email you received does lack context. To make things clearer, I've altered the email content to the following:
Group forum topic
Hi there,
Your forum topic with the subject "SUBJECT":
"EMAIL CONTENT"
Could not be posted because you are no longer a member of the group, "GROUP NAME". To post a new topic via email to this group, please rejoin the group here:
GROUP PERMALINK URL
We apologize for any inconvenience this may have caused.
Group forum reply
Hi there,
Your forum reply:
"EMAIL REPLY"
Could not be posted because you are no longer a member of the group, "GROUP NAME". To comment on the forum thread, please rejoin the group:
GROUP PERMALINK URL
We apologize for any inconvenience this may have caused.
Reference - https://github.com/cuny-academic-commons/cac/commit/c100178ccfd32f2f6f40325beb4d0c3480218df5#diff-8cff9b061cf1317df59a58b00c3533fb
Matt - Let me know if you'd like me to change the email content some more.