I just noticed that there are some delivery errors for a campaign that were not retried but went to "giveup" status. In the campaign overview, "Delivery Error" count is being correctly shown, but once I click on the "view details" button, no email is being listed for any type of "errors". I checked the db and below (image attached) is what I found. There were a couple of such errors in the past. May be the error was due to some network glitch, but I wonder why it wasn't retried.