# Seeing smtp\_should\_reject "400 bad request" failures on bounce processing

**URL:** https://meta.discourse.org/t/seeing-smtp-should-reject-400-bad-request-failures-on-bounce-processing/387431
**Category:** Bug
**Tags:** mail-receiver
**Created:** [November 3, 2025, 7:48am UTC](https://meta.discourse.org/t/seeing-smtp-should-reject-400-bad-request-failures-on-bounce-processing/387431 "2025-11-03T07:48:47Z")
**Posts on this page:** 1
**Showing post:** 21

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### Author: ![supermathie](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/supermathie/32/507518_2.png) [@supermathie](https://meta.discourse.org/u/supermathie)
#### Post date: [November 24, 2025, 5:32pm UTC](https://meta.discourse.org/t/seeing-smtp-should-reject-400-bad-request-failures-on-bounce-processing/387431/21 "2025-11-24T17:32:55Z")

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follow-up here: [Remove smtp\_should\_reject & discourse-smtp-fast-rejection](https://meta.discourse.org/t/remove-smtp-should-reject-discourse-smtp-fast-rejection/389368)

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_[View the full topic](https://meta.discourse.org/t/seeing-smtp-should-reject-400-bad-request-failures-on-bounce-processing/387431)._