A client using Google Apps for email reported to me last week that they had received about 300 spam messages into 3 of their users' inboxes overnight. The 'Remove Spam' function in Gmail now incorporates an automated unsubscriber and while I was the process of flagging these messages as spam, I noticed that the unsubscribe notices were all relating to googlegroups.com domains. My high regard for Google's spam filter had me expecting this problem to be resolved quickly upon reporting the spam, however today my client contacted me again with news of another wave of googlegroups.com spam. I seems that some devious individuals out there have found a loophole in the Google spam filter via Google Groups and have subsequently evaded the usually vigilant spam filter. In the meantime I have found a workaround here, which basically outlines using the Gmail filters function to create a filter to catch all the offending emails and apply a label to them, as well as make them skip the inbox. This then allows a single-click process to report all the emails as spam. Note: Asher's method describes creating a mailing-list-specific filter, however I have found that the spam is coming from multiple google groups lists, so I simply used the text "googlegroups.com" as the filter rule.