RFC 2920
SMTP Service Extension for Command Pipelining
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://statuscodefyi.com/iframe/entity//" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://statuscodefyi.com/entity//Add a dynamic SVG badge to your README or docs.
[](https://statuscodefyi.com/entity//)Use the native HTML custom element.
Abstract
RFC 2920 defines the PIPELINING SMTP service extension, which allows clients to send multiple SMTP commands without waiting for a response to each. This reduces round-trip latency in high-volume mail delivery and improves throughput on high-latency network paths between mail servers.