I've reported this to support twice but (a) it seems to have fallen through the cracks, and (b) I've been very curious about whether other groups are experiencing it, so I am finally posting it here.
When a hashtag is set to reply-to-sender and someone replies via the web, everything works fine (even in a group set to reply-to-group with "remove other reply options" set). However, when people respond via email, some of them - and this seems random - get a bounce message with a groups.io explanation "500: Error: You are not allowed to post to this thread."
This has happened with both yahoo and gmail email addresses. I ran some tests and discovered that in the case I tested that resulted in the error message, the reply actually *did* reach the recipient and that the error message was erroneous. Nevertheless, this has caused great havoc in my group, since we are using this kind of hashtag for condolence messages(*), and people are feeling very upset thinking that their condolences didn't get through, they're trying again, they're contacting me offlist, they're posting about it to the group, etc.
Is anyone else aware that their group is experiencing this problem? It does not happen with every reply - only some of them, and I haven't been able to figure out the circumstances under which it happens. Perhaps the hashtag code is only meant to work with web replies, and not with email? Perhaps it's a simple matter of an erroneous error message, and the error message could simply be eliminated?
(*) we took a page out of Helen's tanyackd playbook for this
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