Can't find the answer to this. Basically when you send an email and the recipient doesn't get it for whatever reason, the server will continue to try and deliver it for 48 hours. Does Campaign Monitor work like this too, or does it give up after the 1st attempt.
It depends on the bounce. As soon as it shows up as a soft bounce in your report, that's it, we aren't going to try again. However, before that happens some servers might bounce back "try again in 2 hours" and in those cases we'll try again before reporting it as a bounce. If the server just bounces back that it's undeliverable for whatever reason, though, we'll just report it as a bounce and stop trying.