On 4/12/05, Matthew Black <black@csulb.edu> wrote:
2. After given a numeric SMTP error response code between 500 and 599 (also known as a "permanent non-delivery response"), the sender must not attempt to retransmit that message to that recipient.
Microsoft Outlook doesn't follow this rule. Outlook perpetually retries sending messages which encounter an SMTP permanent error between 500 and 599. How interesting that their on-line e-mail service has rules that prevent use of the parent company's own products. <8-)
Outlook is not an MTA and it is not going to connect to MSN/Hotmail's servers to deliver mail. And Hotmail is run by a rather different group of people than those that code Outlook. -- Suresh Ramasubramanian (ops.lists@gmail.com)