# 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:** [3 november 2025 om 07:48 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:** 1

<div class="post-metadata">

**Author:** ![DevTeVe](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/devteve/32/487601_2.png) [@DevTeVe](https://meta.discourse.org/u/DevTeVe)\
**Post date:** [3 november 2025 om 07:48 UTC](https://meta.discourse.org/t/seeing-smtp-should-reject-400-bad-request-failures-on-bounce-processing/387431/1 "2025-11-03T07:48:47Z")

</div>

Hi!

I am basically having the exact same issue described here: [Configure direct-delivery incoming email for self-hosted sites with Mail-Receiver - #482 by Carleas](https://meta.discourse.org/t/configure-direct-delivery-incoming-email-for-self-hosted-sites-with-mail-receiver/49487/482)

The problem seems to be that the bounces I am receiving don’t come with a `from` so when the API call is made like `https://forum.example.com/admin/email/smtp_should_reject.json?from=&to=replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com` it returns a 400 with:

```json
{"errors":["param is missing or the value is empty or invalid: from"]}

```

here’s a bit more of the mail-receiver logs

```plaintext
Nov 03 07:34:53 mail postfix/smtpd[1044]: connect from v-108-120-yyy-74-srvr1.xxx.com[74.91.xxx.108]
<19>Nov 3 07:34:53 discourse-smtp-fast-rejection[1048]: Failed to GET smtp_should_reject answer from https://forum.example.com/admin/email/smtp_should_reject.json: 400<22>Nov 3 07:34:53 policyd-spf[1049]: : prepend Received-SPF: None (no SPF record) identity=helo; client-ip=74.91.xxx.108; helo=v-148-29-xxx-192-srvr1.xxx.com; envelope-from=<>; receiver=mail.forum.example.com Nov 03 07:34:53 mail postfix/smtpd[1044]: NOQUEUE: reject: RCPT from v-108-120-yyy-74-srvr1.xxx.com[74.91.xxx.108]: 450 4.7.1 <replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com>: Recipient address rejected: Internal error, API request failed; from=<> to=<replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com> proto=ESMTP helo=<v-148-29-xxx-192-srvr1.xxx.com>

```

However, even if it came with a right `from` (putting my email there) it comes back with

```json
{"reject":true,"reason":"Mail to this address is not accepted. Check the address and try to send again?"}

```

So it would’ve rejected that as well…

Am I missing something on the config? I can’t figure it out

---

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