Mark -- Something has recently broken hashtag settings that used to work.

• If you set a hashtag to "reply only to sender," and subsequently use it, no reply-to field is put in the message header of outgoing emails.
• If you set Hashtag Permissions to "Messages can only be tagged with existing hashtags, others are bounced," incoming emails with new hashtags get forwarded to the group anyway, and the new hashtag is added to the hashtag list.

This was reported by a user in GMF and subsequently confirmed in my test group. I have not thoroughly tested other such settings to see if they may also be malfunctioning.

Regards,
Bruce