On Tue, 3 May 2022, Lyndon Nerenberg (VE7TFX/VE6BBM) wrote:
The pipelining extension came about at a time when networks were slower and latency was higher. And as Gilles says, the only practical application is for dealing with a huge number of RCPT commands. None of those use cases apply any more, so in today's world the extension doesn't really add anything.
When you do have slow, high latency networks (LoRA mesh, etc) there are modern transfer protocols that handle pipelining and high latency. E.g. NNCP (like UUCP but with strong authentication and encryption) is used for mail transfer over slow links much as UUCP was.
