Dominic Raferd: > Has anyone successfully set a delay_warning_time of less than 1 hour (or, > better, less than 30 minutes) without creating a bespoke bounce template?
Unlikely, because that would tell the sender that their message could not be delivered in 0 hours (and using floating point, 0.12 hours, would also look silly). In theory it would be possible to turn the bounce template expander into a programming language, but this is such an unlikely scenario that the development cycles are better spent on things that benefit more people. Wietse