On Oct 28, 2015, at 2:02 PM, John R Levine <johnl@xxxxxxxxx> wrote:
And this is because the SMTP store-and-forward model requires that error messages be delivered asynchronously, which is another architectural problem with SMTP. If error messages could be delivered at the moment of transmission rather than later, at least most of the time, this wouldn’t be an issue. It’s entirely possible to do it, but requires a little more sophistication than Postfix or sendmail have. |