The messages? That's an interesting idea. You can of course look in your group's Members page for a list of the addresses (members) that have met the criteria for the Bouncing (blue B) or Bounced (red B) status.

I'm not entirely certain how one would go about this. I think you'd have to visit each member's subscription page and collect the list of Recent Bounces. Totaling the number of entries in those lists will give you some kind of measure, but it is uncertain due to the word "Recent".

You might want to try and correlate which messages bounced when sent to which members; but I suspect that would turn out to be random.

No.

Email services reject message delivery for many different reasons. Some of the reasons are more or less permanent (that email address has been closed), others are explicitly transient (I'm too busy right now, try again later). The explicitly transient ones Groups.io handles automatically by retrying the delivery of that message to that member later. But eventually Groups.io will give up on those retries, and then it becomes recorded as a "bounce".

Shal

It is a lot easier to deal with if you load it into Excel or a similar program, so that the data is separated into rows and columns.

To see just the members whose email address is on bouncing status, use the drop-menu on the Members page (red arrow) to select the Bouncing list.:

Those members will also appear in the normal Members list, with their red and blue B badges, but they may be widely separated among non-bouncing members.

Shal