For data hygiene purposes, I am trying to put a number on how many times a smart campaign will try to deliver a soft-bouncing email. Whereas one hard bounce is a pretty definitive way to say "this inbox is gone/invalid" - soft bounces are a bit more ambiguous. If, however, I knew that one smart campaign will attempt to deliver an email 3 times, I could make a judgement call and say 9 soft bounces represents the failed delivery of 3 emails, therefore we should remove this record. Appreciate any feedback!
Marketo follows pretty standard soft bounce protocol, which you will see marked as Pending in some reports.
I don't recall where I saw this, but it will send in 1 hr, 2 hrs, 4 hrs, 6 hrs after the original attempt..until it fails after 24 hours.
I usually suspend anyone who soft bounces 3x/30 days. If they do another round, I invalidate them.
Thanks for the feedback, Josh!