On Fri, Oct 11, 2024 at 04:13:48PM -0500, Jay F. Shachter wrote: > The second person said "Greylisting is harmless and only causes a very > small delay in mail delivery. It needs no manual intervention". I do > not know what is the source of this person's information, but it is > clearly a source into which he has deposited much too much confidence, > because his statement is untrue. Greylisting does require manual > intervention. I first have to notice that the recipient's MTA > returned a 400-level error code, and then I have to manually re-send > the mail.
This is not true. All reasonable MTAs will repeat the transmission attempt after a transient error code like 450, in typical configurations after 5 to 15 minutes. If you have to manually resent it, your mail setup is broken. Martin
