Return-Path
The envelope sender address used for bounces and SPF alignment.
Return-Path is the address that receives bounces and is checked for SPF. It can differ from the visible From address. For DMARC to pass via SPF, the Return-Path domain must align with the From domain.
reading this as developers picking email infrastructure
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
Applied to return-path, that means weighing developer experience, SDK breadth, idempotency keys, and operating track record ahead of the rest, against password resets, receipts, and magic links shipped from application code.