Several enhancements I really like for Google Groups:
1. Informative feedback about which post was "rejected". When a mailing list reaches a certain level of activity (like, way too much junks :D), Google groups rejects some posting to slow it down. But the message sent to poster didn't say which post was rejected:
Hello andika at gmail dot com,A copy of subject line will be a helpful hint to poster, if s/he want to try repost later, without having to check mailing list archive.
Your message could not be posted to the indonesian gmail group because there have been too many messages posted to the group recently.
In order to protect the Google Groups service, and the mailboxes of the members of the indonesian gmail group, we limit the number of messages that can be posted per hour to the group.
Please try posting your message later.
If you have questions related to this or any other Google group, please visit the Help Center at http://groups-beta.google.com/support.
The Google Groups Team
2. Mail notifications for moderated groups. When I set a mailing list to allow only member to post, spammers has made some effort to subscribe, then post his/her spams. One way to make this harder is by moderating subscribtion requests. But it need MUCH more effort for moderators to check mailing list management page everytime, to see if there are pending requests. Moderators could be notified by email instead.
3. Thumbnails for image attachments, like we have in GMail, in mail archive. Why does Google Groups treat image attachments differently? I have to download them, then open it using image viewer. Thumbnails will help Google Groups users reduce his/her bandwidth usage. Or maybe it is a trick from Google to make members not to choose "no-mail/web only" type of mailing list membership?