When a group message that is sent to a member through email cannot be delivered, the nondelivery event is called a bounce.

Groups.io deals with these types of bounces:

• Soft bounce: Caused by a problem that is expected to resolve itself automatically after some period of time (such as a temporarily unavailable email server)
• Hard bounce: Caused by an issue that would require human intervention to fix (such as an invalid email address or a full inbox)

Sometimes, it is difficult for Groups.io to determine whether a bounce is soft or hard. In this situation, the system treats it as a soft bounce.

Note: Bouncing affects all groups the member is subscribed to through the Groups.io account that the bouncing email address is registered with. Effectively, the member’s Groups.io account is bouncing.

The overall bounce handling process in Groups.io is:

Step 1: On receiving a bounce for the first time, the system tries to determine—through a combination of the type of bounce and the frequency of the bouncing—whether the account is bouncing often enough and seriously enough to require action.

Step 2: If action is required, the system sets the account’s status to Bouncing, stops sending group emails to it, and begins trying to reach the account holder via bounce probe emails notifying them that the account is bouncing.

Step 3: If the account holder:

• Responds to one of the bounce probes: The account is taken out of bounce handling and goes back to normal.
• Does not respond to any bounce probes within a certain period of time: The system sets the account’s status to Bounced and stops sending emails of any kind to it.

When an account is Bouncing or Bounced, the system takes these actions:

• Logs entries in the activity logs of all the account’s groups stating that the account is bouncing, to inform group moderators.
• Displays a blue B (for a Bouncing account) or a red B (for a Bounced account) next to the account’s email address in the member lists of all its groups.
• Includes the account in the “Bouncing” member lists of its groups. (The account continues to appear in the regular member lists as well.)

The affected members are notified by email that they are Bouncing or Bounced. They are also given a chance to “unbounce” their accounts through a special page at the Groups.io site whenever they are logged in.

! Important: Group owners and moderators cannot do anything to “unbounce” members’ accounts. Members must address the underlying problem themselves.