I want to adjust retry interval, which is currently preset and hard coded by Mailgun
Mailgun is currently trying to deliver this e-mail once every five minutes and getting a temporary failure each time, presumably because the greylisting settings at the remote end require a longer retry interval.
How can we set the retry interval?
"delivery-status" -> "retry-seconds"
The retry interval is hardcoded into Mailgun environment and can not be changed.
Adjusting the value is currently not supported.