goodbye, monthly, and pending subscription messages; define multiple owners and moderators; monitor the group through the activity log and and track email delivery to members; approve messages from moderated users through either the website or via email; set up events in the group calendar and upload files to the Files section; and create a wiki to store group knowledge. Those who have a Slack Team can sync it with their Groups.io group so that when someone joins their group, they will be automatically invited to join the Slack Team and if someone leaves their group, they will be removed from the Slack Team. They can tag message threads by including hashtags in the subject, restrict them to a predefined set, and search archives by tag. They can mute individual threads and hashtags; and receive every message, opt to receive only the first message in a thread with the option to follow the thread later, opt to receive only messages in threads that they start, or opt to receive no emails at all.

Groups.io was launched by Mark Fletcher and is operated from Portola Valley, California, United States.